Prepared by R.R. Donnelley Financial -- Underwriting Agreement, dated November 17, 2003

Equinix, Inc., a corporation organized under the laws of Delaware (the “Company”), proposes to sell to the several underwriters named in Schedule II hereto (the “Underwriters”), for whom you (the “Representatives”) are acting as representatives, the number of shares of Common Stock, $0.001 par value (“Common Stock”), of the Company set forth in Schedule I hereto (said shares to be issued and sold by the Company being hereinafter called the “Underwritten Securities”). The Company also proposes to grant to the Underwriters an option to purchase up to the number of additional shares of Common Stock set forth in Schedule II hereto to cover over-allotments (the “Option Securities”; the Option Securities, together with the Underwritten Securities, being hereinafter called the “Securities”). To the extent there are no additional Underwriters listed on Schedule I other than you, the term Representatives as used herein shall mean you, as Underwriters, and the terms Representatives and Underwriters shall mean either the singular or plural as the context requires. Any reference herein to the Registration Statement, the Basic Prospectus, any Preliminary Final Prospectus or the Final Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Item 12 of Form S-3 which were filed under the Exchange Act on or before the Effective Date of the Registration Statement or the issue date of the Basic Prospectus, any Preliminary Final Prospectus or the Final Prospectus, as the case may be; any reference to the term “Prospectus” means the Basic Prospectus and the Final Prospectus; and any reference herein to the terms “amend”, “amendment” or “supplement” with respect to the Registration Statement, the Basic Prospectus, any Preliminary Final Prospectus or the Final Prospectus shall be deemed to refer to and include the filing of any document under the Exchange Act after the Effective Date of the Registration Statement or the issue date of the Basic Prospectus, any Preliminary Final Prospectus or the Final Prospectus, as the case may be, deemed to be incorporated therein by reference. Certain terms used herein are defined in Section 17 hereof.

SECTION 1. Representations and Warranties. (a) The Company represents and warrants to, and agrees with, each Underwriter as set forth below in this Section 1.

(i) The Company meets the requirements for use of Form S-3 under the Act and has prepared and filed with the Commission a registration statement (the file number of which is set forth in Schedule I hereto) on Form S-3, including a related Basic Prospectus, for registration under the Act of the offering and sale of the Securities. The Company may have filed one or more amendments thereto, including a Preliminary Final Prospectus, each of which has previously been furnished to you. The Company will next file with the Commission a Final Prospectus relating to the Securities in accordance with Rules 415 and 424(b). As filed, such Final Prospectus or such amendment and form of Final Prospectus shall contain all information required by the Act and the rules thereunder, and, except to the extent the Representatives shall agree in writing to a modification, shall be in all substantive respects in the form furnished to you prior to the Execution Time or, to the extent not completed at the Execution Time, shall contain only such specific additional information and other changes (beyond that contained in the Basic Prospectus and any Preliminary Final Prospectus) as the Company has advised you, prior to the Execution Time, will be included or made therein. The Registration Statement, at the Execution Time, meets the requirements set forth in Rule 415(a)(1)(x).

(ii) No order preventing or suspending the use of any Preliminary Final Prospectus has been issued by the Commission, and each Preliminary Final Prospectus, at the time of filing thereof, conformed in all material respects to the requirements of the Act and the rules and regulations of the Commission thereunder, and did not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that this representation and warranty shall not apply to any statements or omissions made in reliance upon and in conformity with information furnished in writing to the Company by an Underwriter through the Representatives expressly for use therein.

(iii) On the Effective Date, the Registration Statement did, and when the Final Prospectus is first filed (if required) in accordance with Rule 424(b) and on the Closing Date (as defined herein) and on any date on which Option Securities are purchased, if such date is not the Closing Date (a “Settlement Date”), the Final Prospectus (and any supplement thereto) will, comply in all material respects with the applicable requirements of the Act and the Exchange Act and the respective rules thereunder; on the Effective Date and at the Execution Time, the

Registration Statement did not or will not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary in order to make the statements therein not misleading; and, on the Effective Date, the Final Prospectus, if not filed pursuant to Rule 424(b), will not, and on the date of any filing pursuant to Rule 424(b) and on the Closing Date and any Settlement Date, the Final Prospectus (together with any supplement thereto) will not, include any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that the Company makes no representations or warranties as to the information contained in or omitted from the Registration Statement or the Final Prospectus (or any supplement thereto) in reliance upon and in conformity with information furnished in writing to the Company by or on behalf of any Underwriter specifically for inclusion in the Registration Statement or the Final Prospectus (or any supplement thereto).

(iv) Otherwise than as set forth or contemplated in the Prospectus, the Company has not sustained since the date of the latest audited financial statements included in the Prospectus any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth or contemplated in the Prospectus; and, since the respective dates as of which information is given in the Registration Statement and the Prospectus, there has not been any change in the capital stock (except pursuant to the exercise of options and warrants), short-term debt, long-term debt, net current assets or net assets of the Company or any material adverse change, or any development involving a prospective material adverse change, in or affecting the general affairs, management, financial position, stockholders’ equity or results of operations of the Company.

(v) Other than as set forth in the Prospectus, the Company has good and marketable title to all personal property owned by it free and clear of all liens, encumbrances and defects except such as are described in the Prospectus or such as do not materially affect the value of such property and do not interfere with the use made and proposed to be made of such property by the Company; and any real property and buildings held under lease by the Company are held by them under valid, subsisting and enforceable leases with such exceptions as are not material and do not interfere with the use made and proposed to be made of such property and buildings by the Company.

(vi) The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of Delaware, with power and authority (corporate and other) to own its properties and conduct its business as described in the Prospectus, and has been duly qualified as a foreign corporation for the transaction of business and is in good standing under the laws of each other jurisdiction in which it owns or leases properties or conducts any business so as to require such qualification, or is subject to no material liability or disability by reason of the failure to be so qualified in any such jurisdiction.

(vii) The Company has an authorized capitalization as set forth in the Prospectus, and all of the issued shares of capital stock of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and the Securities conform to the description of the Common Stock contained in the Prospectus.

(viii) The Securities have been duly and validly authorized and, when issued and delivered against payment therefor as provided herein, will be duly and validly issued and fully paid and non-assessable and will conform to the description of the Securities contained in the Prospectus.

(ix) The issue and sale of the Securities by the Company and the compliance by the Company with all of the provisions of this Agreement and the consummation of the transactions contemplated herein will not conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company is a party or by which the Company is bound or to which any of the property or assets of the Company is subject, except for such breach, violation or default as would not have a material adverse effect on the business, financial condition, results of operations or prospects of the Company or its performance of its obligations hereunder, nor will such action result in any violation of the provisions of the Certificate of Incorporation or Bylaws of the Company or any statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over the Company or any of its properties; and no consent, approval, authorization, order, registration or qualification of or with any such court or governmental agency or body is required for the issue and sale of the Securities or the consummation by the Company of the transactions contemplated herein, except the registration under the Act of the Securities and such consents, approvals, authorizations, registrations or qualifications as may be required under state securities or Blue Sky laws in connection with the purchase and distribution of the Securities by the Underwriters.

(x) The Company is not in violation of its Certificate of Incorporation, Bylaws or other organizational documents or in default in the performance or observance of any material obligation, agreement, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement, lease or other agreement or instrument to which it is a party or by which it or any of its properties may be bound.

(xi) The statements set forth in the Prospectus under the caption “Description of Securities to be Registered”, insofar as they purport to constitute a summary of the terms of the Securities and under the captions “Underwriting” and “Shares Eligible for Future Sale” insofar as they purport to describe the provisions of the laws and documents referred to therein, are accurate, complete and fair.

(xii) Other than as set forth in the Prospectus, there are no legal or governmental proceedings pending to which the Company is a party or of which any property of the Company is the subject which, if determined adversely to the Company, would individually or in the aggregate have a material adverse effect on the current or future financial position, stockholders’ equity or results of operations of the Company; and, to the Company’s knowledge, no such proceedings are threatened or contemplated by governmental authorities or threatened by others.

(xiii) The Company is not and, after giving effect to the offering and sale of the Securities, will not be an “investment company”, as such term is defined in the Investment Company Act of 1940, as amended (the “Investment Company Act”).

(xiv) Neither the Company nor any of its affiliates does business with the government of Cuba or with any person or affiliate located in Cuba within the meaning of Section 517.075, Florida Statutes.

(xv) PricewaterhouseCoopers, LLP, who have certified certain financial statements of the Company, are independent public accountants as required by the Act and the rules and regulations of the Commission thereunder.

(xvi) The Company maintains a system of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

(xvii) Except as otherwise disclosed in the Prospectus, the Company owns or possesses adequate rights to use, all material trademarks, service marks, trademark registrations, service mark registrations, domain names, copyrights, licenses, inventions and know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures) necessary for the conduct of its business as described in the Prospectus, and the Company has no reason to believe that the conduct of its business will conflict with, and has not received any notice of any claim of conflict with, any such rights of others, except any failure or conflict as would not, individually or in the aggregate, have a material adverse effect on the business, financial condition, results of operations or prospects of the Company (a “Material Adverse Effect”); and to its knowledge, the Company has not infringed or is not infringing any trademarks, service marks, trademark registrations, service mark registrations, domain names or copyrights, which infringement could reasonably be expected to result in a material adverse change in or affecting the general affairs, financial position, stockholder’s equity or results of operations of the Company.

(xviii) Except as otherwise disclosed in the Prospectus, to its knowledge the Company possesses adequate rights to use all material patents necessary for the conduct of its business; to its knowledge, no valid United States patent is or would be infringed by the activities of the Company, except any failure or infringement as would not, individually or in the aggregate, have a Material Adverse Effect; there are no actions, suits or proceedings pending relating to patents or proprietary information to which the Company is a party or of which any property of the Company is subject and, to its knowledge, no such actions, suits or proceedings are threatened by governmental authorities or others; the Company is not aware of any claim by others that the Company is infringing or otherwise violating the patents or other intellectual property of others and is not aware of any rights of third parties to any of its licensed patents or licenses which could materially affect its use thereof.

(xix) No labor dispute with the employees of the Company exists or, to the knowledge of the Company, is imminent.

(xx) Other than its wholly-owned subsidiaries, the Company does not own any shares of capital in or any interest in any corporation, partnership, association, joint venture or other business entity.

(xxi) Except as disclosed in the Prospectus, there are no contracts, agreements or understandings between the Company and any person granting such person the right to require the Company to file a registration statement under the Act with respect to any securities of the Company owned or to be owned by such person or to require the Company to include such securities in the securities registered pursuant to a Registration Statement or in any securities being registered pursuant to any other registration statement filed by the Company under the Act, other than those that have been effectively satisfied or waived in writing.

(xxii) This Agreement has been duly authorized, executed and delivered by the Company.

(xxiii) Other than fixed assets taxes relating to the Company’s Japan IBX, which taxes are currently under review by the Company, the Company has filed all foreign, federal, state and local tax returns that are required to be filed or has requested extensions thereof and has paid all taxes required to be paid by it and any other assessment, fine or penalty levied against it, to the extent that any of the foregoing is due and payable, except for any such assessment, fine or penalty that is currently being contested in good faith or as would not, individually or in the aggregate, have a Material Adverse Effect.

(xxiv) The Company is insured by insurers of recognized financial responsibility; the Company has no reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at a cost that would not have a material adverse effect on its current or future financial position, stockholders equity or results of operations.

(xxv) The Company is not aware of any material fact with respect to the patent applications of the Company presently on file that (a) would preclude the issuance of patents with respect to such applications or (b) would lead such counsel to conclude that such patents, when issued, would not be valid and enforceable in accordance with applicable regulations.

(xxvi) Each of Equinix-DC, Inc., a Delaware corporation, and Equinix OpCo, Inc., a Delaware corporation, has been duly incorporated or formed and is validly existing as a corporation in good standing under the laws of their respective jurisdictions of incorporation; and the issued and outstanding equity interests of Equinix-DC, Inc. and Equinix OpCo, Inc. owned by the Company have been duly authorized and validly issued, is fully paid and non-assessable, and except as disclosed in the Prospectus, the Company owns such interests, free and clear of all liens, encumbrances, equities or claims.

Any certificate signed by any officer of the Company and delivered to the Representatives or counsel for the Underwriters in connection with the offering of the Securities shall be deemed a representation and warranty by the Company, as to matters covered thereby, to each Underwriter.

(b) Each Underwriter, severally and not jointly, represents, warrants and covenants to the Company that:

(i) It has not offered or sold and, prior to the expiry of a period of six months from the Closing Date, will not offer or sell any Securities to persons in the United Kingdom except to persons whose ordinary activities involve them in acquiring, holding, managing or disposing of investments (as principal or agent) for the purposes of their businesses or otherwise in circumstances which have not resulted and will not result in an offer to the public in the United Kingdom within the meaning of the Public Offers of Securities Regulations 1995.

(ii) It has only communicated and caused to be communicated and will only communicate or cause to be communicated any invitation or inducement to engage in investment activity (within the meaning of section 21 of the Financial Services and Markets Act 2000 (“FSMA”‘)) received by it in connection with the issue or sale of the Securities in circumstances in which section 21(1) of the FSMA does not apply to the Company.

(iii) It has complied and will comply with all applicable provisions of the FSMA with respect to anything done by it in relation to the Securities in, from or otherwise involving the United Kingdom.

(iv) It has exclusively limited the offer of the Securities in The Netherlands to persons who trade or invest in securities in the conduct of a profession or business (which include banks, stockbrokers, insurance companies, pension funds, other institutional investors and finance companies and treasury departments of large enterprises).

SECTION 2. Purchase and Sale. (a) Subject to the terms and conditions and in reliance upon the representations and warranties herein set forth, the Company agrees to sell to each Underwriter, and each Underwriter agrees, severally and not jointly, to purchase from the Company, at a purchase price of $18.888 per share, the amount of the Underwritten Securities set forth opposite such Underwriter’s name in Schedule II hereto of which the Underwriters agree 1,535,948 shares shall be sold to i-STT Investments Pte. Ltd., an affiliate of STT Communications, Ltd. (“STT”).

(b) Subject to the terms and conditions and in reliance upon the representations and warranties herein set forth, the Company hereby grants an option to the several Underwriters to purchase, severally and not jointly, up to 675,000 Option Securities at the same purchase price per share as the Underwriters shall pay for the Underwritten Securities. Said option may be exercised only to cover over-allotments in the sale of the Underwritten Securities by the Underwriters. Said option may be exercised in whole or in part at any time on or before the 30th day after the date of the Prospectus upon written or telegraphic notice by the Representatives to the Company setting forth the number of shares of the Option Securities as to which the several Underwriters are exercising the option and the Settlement Date. The number of shares of the Option Securities to be purchased by each Underwriter shall be the same percentage of the total number of shares of the Option Securities to be purchased by the several Underwriters as such Underwriter is purchasing of the Underwritten Securities, subject to such adjustments as you in your absolute discretion shall make to eliminate any fractional shares.

SECTION 3. Delivery and Payment. Delivery of and payment for the Underwritten Securities and the Option Securities (if the option provided for in Section 2(b) hereof shall have been exercised on or before the third Business Day prior to the Closing Date) shall be made on the date and at the time specified in Schedule I hereto or at such time on such later date not more than three Business Days after the foregoing date as the Representatives shall designate, which date and time may be postponed by agreement between the Representatives and the Company or as provided in Section 9 hereof (such date and time of delivery and payment for the Securities being herein called the “Closing Date”). Delivery of the Securities shall be made to the Representatives for the respective accounts of the several Underwriters against payment by the several Underwriters through the Representatives of the purchase price thereof to or upon the order of the Company by wire transfer payable in same-day funds to an account specified by the Company. Delivery of the Underwritten Securities and the Option Securities shall be made through the facilities of The Depository Trust Company unless the Representatives shall otherwise instruct.

If the option provided for in Section 2(b) hereof is exercised after the third Business Day prior to the Closing Date, the Company will deliver the Option Securities (at the expense of the Company) to the Representatives for the respective accounts of the several Underwriters against payment by the several Underwriters through the Representatives of the purchase price thereof to or upon the order of the Company by wire transfer payable in same-day funds to an account specified by the Company. If settlement for the Option Securities occurs after the Closing Date, the Company will deliver to the Representatives on the Settlement Date for the Option Securities, and the obligation of the Underwriters to purchase the Option Securities shall be conditioned upon receipt of, supplemental opinions, certificates and letters confirming as of such date the opinions, certificates and letters delivered on the Closing Date pursuant to Section 6 hereof.

SECTION 4. Offering by Underwriters. It is understood that the several Underwriters propose to offer the Securities for sale to the public as set forth in the Final Prospectus.

(a) The Company will use its best efforts to cause the Registration Statement, if not effective at the Execution Time, and any amendment thereof, to become effective. Prior to the termination of the offering of the Securities, the Company will not file any amendment of the Registration Statement or supplement (including the Final Prospectus or any Preliminary Final Prospectus) to the Basic Prospectus or any Rule 462(b) Registration Statement unless the Company has furnished the Representatives a copy for their review prior to filing and will not file any such proposed amendment or supplement to which the Representatives reasonably object. Subject to the foregoing sentence, if the filing of the Final Prospectus is required under Rule 424(b), the Company will cause the Final Prospectus, properly completed, and any supplement thereto to be filed in a form approved by the Representatives with the Commission pursuant to the applicable paragraph of Rule 424(b) within the time period prescribed and will provide evidence satisfactory to the Representatives of such timely filing. The Company will promptly advise the Representatives (1) when the Registration Statement, if not effective at the Execution Time, shall have become effective, (2) when the Final Prospectus, and any supplement thereto, shall have been filed (if required) with the Commission pursuant to Rule 424(b) or when any Rule 462(b) Registration Statement shall have been filed with the Commission, (3) when, prior to termination of the offering of the Securities, any amendment to the Registration Statement shall have been filed or become effective, (4) of any request by the Commission or its staff for any amendment of the Registration Statement, or any Rule 462(b) Registration Statement, or for any supplement to the Final Prospectus or for any additional information, (5) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or the institution or threatening of any proceeding for that purpose and (6) of the receipt by the Company of any notification with respect to the suspension of the qualification of the Securities for sale in any jurisdiction or the institution or threatening of any proceeding for such purpose. The Company will use its best efforts to prevent the issuance of any such stop order or the suspension of any such qualification and, if issued, to obtain as soon as possible the withdrawal thereof.

(b) If, at any time when a prospectus relating to the Securities is required to be delivered under the Act, any event occurs as a result of which the Final Prospectus as then supplemented would include any untrue statement of a material fact or omit to state any material fact necessary to make the statements therein in the light of the circumstances under which they were made not misleading, or if it shall be necessary to

amend the Registration Statement or supplement the Final Prospectus to comply with the Act or the Exchange Act or the respective rules thereunder, the Company promptly will (1) notify the Representatives of such event, (2) prepare and file with the Commission, subject to the second sentence of paragraph (a) of this Section 5, an amendment or supplement which will correct such statement or omission or effect such compliance and (3) supply any supplemented Final Prospectus to the Representatives in such quantities as they may reasonably request.

(c) As soon as practicable, the Company will make generally available to its security holders and to the Representatives an earnings statement or statements of the Company and its subsidiaries which will satisfy the provisions of Section 11(a) of the Act and Rule 158 under the Act.

(d) The Company will furnish to the Representatives and counsel for the Underwriters, without charge, signed copies of the Registration Statement (including exhibits thereto) and to each other Underwriter a copy of the Registration Statement (without exhibits thereto) and, so long as delivery of a prospectus by an Underwriter or dealer may be required by the Act, as many copies of each Preliminary Final Prospectus and the Final Prospectus and any supplement thereto as the Representatives may reasonably request. The Company will pay the expenses of printing or other production of all documents relating to the offering; provided, however, that the Underwriters agree to reimburse the Company in the amount of $350,000 for expenses incurred by the Company in connection with the offering.

(e) The Company will arrange, if necessary, for the qualification of the Securities for sale under the laws of such jurisdictions as the Representatives may designate, will maintain such qualifications in effect so long as required for the distribution of the Securities and will pay any fee of the National Association of Securities Dealers, Inc., in connection with its review of the offering; provided that in no event shall the Company be obligated to qualify to do business in any jurisdiction where it is not now so qualified or to take any action that would subject it to service of process in suits, other than those arising out of the offering or sale of the Securities, in any jurisdiction where it is not now so subject.

(f) Except as set forth in Exhibit C (“Permitted Issuances”), the Company will not, without the prior written consent of Citigroup Global Markets Inc., offer, sell, contract to sell, pledge, or otherwise dispose of, (or enter into any transaction which is designed to, or might reasonably be expected to, result in the disposition (whether by actual disposition or effective economic disposition due to cash settlement or otherwise) by the Company or any affiliate of the Company or any person in privity with the Company or any affiliate of the Company) directly or indirectly, including the filing (or participation in the filing) of a registration statement with the Commission in respect of, or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Exchange Act, any other shares of Common Stock or any securities convertible into, or exercisable, or exchangeable for, shares of Common Stock; or publicly announce an intention to effect any such transaction, until the Business Day set forth on Schedule I hereto.

(g) For a period of 90 days after the date of this agreement, the Company will not take, directly or indirectly, any action designed to or that would constitute or that might reasonably be expected to cause or result in, under the Exchange Act or otherwise, stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Securities.

SECTION 6. Conditions to the Obligations of the Underwriters. The obligations of the Underwriters to purchase the Underwritten Securities and the Option Securities, as the case may be, shall be subject to the accuracy of the representations and warranties on the part of the Company contained herein as of the Execution Time, the Closing Date and any settlement date pursuant to Section 3 hereof, to the accuracy of the statements of the Company made in any certificates pursuant to the provisions hereof, to the performance by the Company of its obligations hereunder and to the following additional conditions:

(a) If the Registration Statement has not become effective prior to the Execution Time, unless the Representatives agree in writing to a later time, the Registration Statement will become effective not later than (i) 6:00 PM New York City time on the date of determination of the public offering price, if such determination occurred at or prior to 3:00 PM New York City time on such date or (ii) 9:30 AM on the Business Day following the day on which the public offering price was determined, if such determination occurred after 3:00 PM New York City time on such date; if filing of the Final Prospectus, or any supplement thereto, is required pursuant to Rule 424(b), the Final Prospectus, and any such supplement, will be filed in the manner and within the time period required by Rule 424(b); and no stop order suspending the effectiveness of the Registration Statement shall have been issued and no proceedings for that purpose shall have been instituted or threatened.

(b) The Company shall have requested and caused Gunderson Dettmer Stough Villeneuve Franklin & Hachigian LLP, counsel for the Company, to have furnished to the Representatives their opinion, dated the Closing Date and addressed to the Representatives, to the effect that:

(i) The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of Delaware, with power and authority to own its properties and conduct its business as described in the Prospectus;

(ii) The Company has an authorized capitalization as set forth in the Prospectus, and all of the issued shares of capital stock of the Company (including the Securities being delivered at the Closing Date) have been duly and validly authorized and issued and are, to its knowledge, fully paid and non-assessable; and the Securities conform in all material respects to the description of the Securities contained in the Prospectus;

(iii) The Company has been duly qualified as a foreign corporation for the transaction of business and is in good standing under the laws of California, Illinois, New Jersey, New York, Ohio, Texas and Virginia;

(iv) To such counsel’s knowledge and other than as set forth in the Prospectus, there are no legal or governmental proceedings pending to which the Company is a party which, if determined adversely to the Company, would individually or in the aggregate have a Material Adverse Effect; and, to such counsel’s knowledge, no such proceedings are threatened by governmental authorities or threatened by others;

(v) This Agreement has been duly authorized, executed and delivered by the Company;

(vi) The issue and sale of the Securities being delivered at the Closing Date by the Company and the compliance by the Company with all of the provisions of this Agreement and the consummation of the transactions contemplated herein will not result in any violation of the provisions of the Certificate of Incorporation or Bylaws of the Company or any statute or any order, rule or regulation known to such counsel of any court or governmental agency or body having jurisdiction over the Company or any of its properties;

(vii) No consent, approval, authorization, order, registration or qualification of or with any such court or governmental agency or body is required for the issue and sale of the Securities or the consummation by the Company of the transactions contemplated by this Agreement, except the registration under the Act of the Securities, and such consents, approvals, authorizations, registrations or qualifications as may be required under state securities or Blue Sky laws in connection with the purchase and distribution of the Securities by the Underwriters;

(viii) To such counsel’s knowledge, the Company is not in violation of its Certificate of Incorporation or Bylaws;

(ix) The statements set forth in the Prospectus under the caption “Description of Securities to be Registered”, insofar as they purport to constitute a summary of the terms of the Common Stock and under the caption “Underwriting” and “Shares Eligible for Future Sale” insofar as they purport to describe the provisions of the laws and documents referred to therein, are accurate and complete in all material respects;

(x) The Company is not an “investment company”, as such term is defined in the Investment Company Act; and

(xi) The Registration Statement and the Prospectus and any further amendments and supplements thereto made by the Company prior to the Closing Date (other than the financial statements and related schedules thereto and the financial data derived from the financial statements included therein, as to which such counsel need express no belief) comply as to form in all material respects with the requirements of the Act and the rules and regulations thereunder; although they do not assume any responsibility for the accuracy, completeness or fairness of the statements contained in the Registration Statement or the Prospectus,

except for those referred to in the opinion in subsection (ix) of this section 6(b), they have no reason to believe that, as of its effective date, the Registration Statement or any further amendment thereto made by the Company prior to the Closing Date (other than the financial statements and related schedules thereto and the financial data derived from the financial statements included therein or other financial data, as to which such counsel need express no opinion) contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading or that, as of its date, the Prospectus or any further amendment or supplement thereto made by the Company prior to the Closing Date (other than the financial statements and related schedules thereto and the financial data derived from the financial statements included therein or other financial data, as to which such counsel need express no opinion) contained an untrue statement of a material fact or omitted to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading or that, as of the Closing Date, either the Registration Statement or the Prospectus or any further amendment or supplement thereto made by the Company prior to the Closing Date (other than the financial statements and related schedules thereto and the financial data derived from the financial statements included therein or other financial data, as to which such counsel need express no opinion) contains an untrue statement of a material fact or omits to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; and they do not know of any contracts or other documents of a character required to be filed as an exhibit to the Registration Statement or required to be described in the Registration Statement or the Prospectus which are not filed or described as required.

(c) The Company shall have requested and caused Brandi L. Galvin, General Counsel for the Company, to have furnished to the Representatives her opinion, dated the Closing Date and addressed to the Representatives, to the effect that:

(i) The issue and sale of the Securities being delivered at the Closing Date by the Company and the compliance by the Company with all of the provisions of this Agreement and the consummation of the transactions contemplated herein will not result in a breach or violation of any of the terms or provisions of, or constitute a default under, any agreement or instrument filed as an exhibit to the Registration Statement or as an exhibit to the Company’s Form 10-K/A for the year ended December 31, 2002 and which are not the subject of the opinions to be delivered pursuant to Sections 6(b) or 6(d) hereof; and

(ii) To such counsel’s knowledge, the Company is not in default in the performance or observance of any material obligation, agreement, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement, lease or other agreement or instrument filed as an exhibit to the Registration Statement or the Company’s Form 10-K/A for the year ended December 31, 2002 to which it is a party or by which it or any of its properties may be bound.

(d) The Company shall have requested and caused Willkie, Farr & Gallagher, counsel to the Company, to have furnished to the Representatives their opinion, dated the Closing Date and addressed to the Representatives, to the effect that the issue and sale of the Securities being delivered at the Closing Date by the Company and the compliance by the Company with all of the provisions of this Agreement and the consummation of the transactions contemplated herein will not result in a breach or violation of any of the terms or provisions of, or constitute a default under, the Amended and Restated Credit and Guaranty Agreement, dated as of September 30, 2001, as amended, and the Indenture, dated as of December 1, 1999, providing for the issuance thereunder by the Company and the authentication and delivery by the Trustee, of the Company’s 13% Senior Notes due 2007, as amended by the First Supplemental Indenture, dated as of December 28, 2002.

(e) The Representatives shall have received from Cahill Gordon & Reindel LLP, counsel for the Underwriters, such opinion or opinions, dated the Closing Date and addressed to the Representatives, with respect to the issuance and sale of the Securities, the Registration Statement, the Final Prospectus (together with any supplement thereto) and other related matters as the Representatives may reasonably require, and the Company shall have furnished to such counsel such documents as they reasonably request for the purpose of enabling them to pass upon such matters.

(f) The Company shall have furnished to the Representatives a certificate of the Company, signed by the Chief Executive Officer or the President and the principal financial or accounting officer of the Company, dated the Closing Date, to the effect that the signers of such certificate have carefully examined the Registration Statement, the Final Prospectus, any supplements to the Final Prospectus and this Agreement and that:

(i) the representations and warranties of the Company in this Agreement are true and correct on and as of the Closing Date with the same effect as if made on the Closing Date and the Company has complied with all the agreements and satisfied all the conditions on its part to be performed or satisfied at or prior to the Closing Date;

(ii) no stop order suspending the effectiveness of the Registration Statement has been issued and no proceedings for that purpose have been instituted or, to the Company’s knowledge, threatened; and

(iii) since the date of the most recent financial statements included or incorporated by reference in the Final Prospectus (exclusive of any supplement thereto), there has been no Material Adverse Effect.

(g) At the Execution Time and also on the Closing Date, PricewaterhouseCoopers LLP shall have furnished to the Underwriters letters, dated the respective dates of delivery thereof, in form and substance satisfactory to you, containing statements and information of the type customarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement and the Prospectus;

(h) Subsequent to the Execution Time or, if earlier, the dates as of which information is given in the Registration Statement (exclusive of any amendment thereof) and the Final Prospectus (exclusive of any supplement thereto), there shall not have been (i) any change or decrease specified in the letter or letters referred to in paragraph (e) of this Section 6 or (ii) any change, or any development involving a prospective change, in or affecting the condition (financial or otherwise), earnings, business or properties of the Company and its subsidiaries, taken as a whole, whether or not arising from transactions in the ordinary course of business, except as set forth in or contemplated in the Final Prospectus (exclusive of any supplement thereto) the effect of which, in any case referred to in clause (i) or (ii) above, is, in the sole judgment of the Representatives, so material and adverse as to make it impractical or inadvisable to proceed with the offering or delivery of the Securities as contemplated by the Registration Statement (exclusive of any amendment thereof) and the Final Prospectus (exclusive of any supplement thereto).

(i) Prior to the Closing Date, the Company shall have furnished to the Representatives such further information, certificates and documents as the Representatives may reasonably request.

(j) The Securities to be delivered on the Closing Date shall have been approved for listing on the Nasdaq National Market, subject only to official notice of issuance.

(k) At the Execution Time, the Company shall have furnished to the Representatives a letter substantially in the form of Exhibit A hereto (or such other form that has been previously approved by a Representative) from each officer and director of the Company and the stockholders listed on Exhibit B addressed to the Representatives.

If any of the conditions specified in this Section 6 shall not have been fulfilled when and as provided in this Agreement, or if any of the opinions and certificates mentioned above or elsewhere in this Agreement shall not be in reasonably satisfactory in form and substance to the Representatives and counsel for the Underwriters, this Agreement and all obligations of the Underwriters hereunder may be canceled on the Closing Date by the Representatives. Notice of such cancellation shall be given to the Company in writing or by telephone or facsimile confirmed in writing.

The documents required to be delivered by this Section 6 shall be delivered at the office of Cahill Gordon & Reindel LLP, counsel for the Underwriters, at Eighty Pine Street, New York, New York 10005, on the Closing Date.

SECTION 7. Reimbursement of Underwriters’ Expenses. If the sale of the Securities provided for herein is not consummated because any condition to the obligations of the Underwriters set forth in Section 6 hereof is not satisfied, because of any termination pursuant to Section 10 hereof or because of any refusal, inability or failure on the part of the Company to perform any agreement herein or comply with any provision hereof other than by reason of a default by any of the Underwriters, the Company will reimburse the Underwriters severally through Citigroup Global Markets Inc. on demand for all out-of-pocket expenses (including reasonable fees and disbursements of counsel) that shall have been incurred by them in connection with the proposed purchase and sale of the Securities.

SECTION 8. Indemnification and Contribution. (a) The Company agrees to indemnify and hold harmless each Underwriter, the directors, officers, employees and agents of each Underwriter and each person who controls any Underwriter within the meaning of either the Act or the Exchange Act against any and all losses, claims, damages or liabilities, joint or several, to which they or any of them may become subject under the Act, the Exchange Act or other Federal or state statutory law or regulation, at common law or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement for the registration of the Securities as originally filed or in any amendment thereof, or in the Basic Prospectus, any Preliminary Final Prospectus or the Final Prospectus, or in any amendment thereof or supplement thereto, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, and agrees to reimburse each such indemnified party, as incurred, for any legal or other expenses reasonably incurred by them in connection with investigating or defending any such loss, claim, damage, liability or action; provided, however, that the Company will not be liable in any such case to the extent that any such loss, claim, damage or liability arises out of or is based upon any such untrue statement or alleged untrue statement or omission or alleged omission made therein in reliance upon and in conformity with written information furnished to the Company by or on behalf of any Underwriter through the Representatives specifically for inclusion therein. This indemnity agreement will be in addition to any liability which the Company may otherwise have.

(b) Each Underwriter severally and not jointly agrees to indemnify and hold harmless the Company, each of its directors, each of its officers who signs the Registration Statement, and each person who controls the Company within the meaning of either the Act or the Exchange Act, to the same extent as the foregoing indemnity from the Company to each Underwriter, but only with reference to written information relating to such Underwriter furnished to the Company by or on behalf of such Underwriter through the Representatives specifically for inclusion in the documents referred to in the foregoing indemnity. This indemnity agreement will be in addition to any liability which any Underwriter may otherwise have. The Company acknowledges that the statements set forth in the last paragraph of the cover page regarding delivery of the Securities and, under the heading “Underwriting”, (i) the list of Underwriters and their respective participation in the sale of the Securities, (ii) the sentences related to concessions and reallowances and (iii) the paragraph related to stabilization, syndicate covering transactions and penalty bids in any Preliminary Final Prospectus and the Final Prospectus constitute the only information furnished in writing by or on behalf of the several Underwriters for inclusion in any Preliminary Final Prospectus or the Final Prospectus.

(c) Promptly after receipt by an indemnified party under this Section 8 of notice of the commencement of any action, such indemnified party will, if a claim in respect thereof is to be made against the indemnifying party under this Section 8, notify the indemnifying party in writing of the commencement thereof; but the failure so to notify the indemnifying party (i) will not relieve it from liability under paragraph (a) or (b) above unless and to the extent it did not otherwise learn of such action and such failure results in the forfeiture

by the indemnifying party of substantial rights and defenses and (ii) will not, in any event, relieve the indemnifying party from any obligations to any indemnified party other than the indemnification obligation provided in paragraph (a) or (b) above. The indemnifying party shall be entitled to appoint counsel of the indemnifying party’s choice at the indemnifying party’s expense to represent the indemnified party in any action for which indemnification is sought (in which case the indemnifying party shall not thereafter be responsible for the fees and expenses of any separate counsel retained by the indemnified party or parties except as set forth below); provided, however, that such counsel shall be satisfactory to the indemnified party. Notwithstanding the indemnifying party’s election to appoint counsel to represent the indemnified party in an action, the indemnified party shall have the right to employ separate counsel (including local counsel) and the indemnifying party shall bear the reasonable fees, costs and expenses of such separate counsel if (i) the use of counsel chosen by the indemnifying party to represent the indemnified party would present such counsel with a conflict of interest, (ii) the actual or potential defendants in, or targets of, any such action include both the indemnified party and the indemnifying party and the indemnified party shall have reasonably concluded that there may be legal defenses available to it and/or other indemnified parties which are different from or additional to those available to the indemnifying party, (iii) the indemnifying party shall not have employed counsel satisfactory to the indemnified party to represent the indemnified party within a reasonable time after notice of the institution of such action or (iv) the indemnifying party shall authorize the indemnified party to employ separate counsel at the expense of the indemnifying party. An indemnifying party will not, without the prior written consent of the indemnified parties, settle or compromise or consent to the entry of any judgment with respect to any pending or threatened claim, action, suit or proceeding in respect of which indemnification or contribution may be sought hereunder (whether or not the indemnified parties are actual or potential parties to such claim or action) unless such settlement, compromise or consent includes an unconditional release of each indemnified party from all liability arising out of such claim, action, suit or proceeding.

(d) In the event that the indemnity provided in paragraph (a), (b) or (c) of this Section 8 is unavailable to or insufficient to hold harmless an indemnified party for any reason, the Company and the Underwriters severally agree to contribute to the aggregate losses, claims, damages and liabilities (including legal or other expenses reasonably incurred in connection with investigating or defending same) (collectively “Losses”) to which the Company and one or more of the Underwriters may be subject in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and by the Underwriters on the other from the offering of the Securities; provided, however, that in no case shall any Underwriter (except as may be provided in any agreement among underwriters relating to the offering of the Securities) be responsible for any amount in excess of the underwriting discount or commission applicable to the Securities purchased by such Underwriter hereunder. If the allocation provided by the immediately preceding sentence is unavailable for any reason, the Company and the Underwriters severally shall contribute in such proportion as is appropriate to reflect not only such relative benefits but also the relative fault of the Company on the one hand and of the Underwriters on the other in connection with the statements or omissions which resulted in such Losses as well as any other relevant equitable considerations. Benefits received by the Company shall be deemed to be equal to the total net proceeds from the offering (before deducting expenses) received by it, and benefits received by the Underwriters shall be deemed to be equal to the total underwriting discounts and commissions, in each case as set forth in the Final

Prospectus. Relative fault shall be determined by reference to, among other things, whether any untrue or any alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information provided by the Company on the one hand or the Underwriters on the other, the intent of the parties and their relative knowledge, access to information and opportunity to correct or prevent such untrue statement or omission. The Company and the Underwriters agree that it would not be just and equitable if contribution were determined by pro rata allocation or any other method of allocation which does not take account of the equitable considerations referred to above. Notwithstanding the provisions of this paragraph (d), no person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. For purposes of this Section 8, each person who controls an Underwriter within the meaning of either the Act or the Exchange Act and each director, officer, employee and agent of an Underwriter shall have the same rights to contribution as such Underwriter, and each person who controls the Company within the meaning of either the Act or the Exchange Act, each officer of the Company who shall have signed the Registration Statement and each director of the Company shall have the same rights to contribution as the Company, subject in each case to the applicable terms and conditions of this paragraph (d).

SECTION 9. Default by an Underwriter. If any one or more Underwriters shall fail to purchase and pay for any of the Securities agreed to be purchased by such Underwriter or Underwriters hereunder and such failure to purchase shall constitute a default in the performance of its or their obligations under this Agreement, the remaining Underwriters shall be obligated severally to take up and pay for (in the respective proportions which the amount of Securities set forth opposite their names in Schedule II hereto bears to the aggregate amount of Securities set forth opposite the names of all the remaining Underwriters) the Securities which the defaulting Underwriter or Underwriters agreed but failed to purchase; provided, however, that in the event that the aggregate amount of Securities which the defaulting Underwriter or Underwriters agreed but failed to purchase shall exceed 10% of the aggregate amount of Securities set forth in Schedule II hereto, the remaining Underwriters shall have the right to purchase all, but shall not be under any obligation to purchase any, of the Securities, and if such nondefaulting Underwriters do not purchase all the Securities, this Agreement will terminate without liability to any nondefaulting Underwriter or the Company, provided further, however, that prior to such termination the Company shall be entitled to a period of thirty-six hours within which to procure another party or other parties satisfactory to the non-defaulting Underwriters to purchase such shares on such terms. In the event of a default by any Underwriter as set forth in this Section 9, the Closing Date shall be postponed for such period, not exceeding five Business Days, as the Representatives shall determine in order that the required changes in the Registration Statement and the Final Prospectus or in any other documents or arrangements may be effected. Nothing contained in this Agreement shall relieve any defaulting Underwriter of its liability, if any, to the Company and any nondefaulting Underwriter for damages occasioned by its default hereunder.

SECTION 10. Termination. This Agreement shall be subject to termination in the absolute discretion of the Representatives, by notice given to the Company prior to delivery of and payment for the Securities, if at any time prior to such time (i) trading in the Company’s Common Stock shall have been suspended by the Commission or the Nasdaq National Market or trading in securities generally on the Nasdaq National Market shall have been suspended or limited or minimum prices shall have been established on the Nasdaq National Market, (ii) a

banking moratorium shall have been declared either by Federal or New York State authorities or (iii) there shall have occurred any outbreak or escalation of hostilities, declaration by the United States of a national emergency or war, or other calamity or crisis the effect of which on financial markets is such as to make it, in the sole judgment of the Representatives, impractical or inadvisable to proceed with the offering or delivery of the Securities as contemplated by the Final Prospectus (exclusive of any supplement thereto).

SECTION 11. Representations and Indemnities to Survive. The respective agreements, representations, warranties, indemnities and other statements of the Company or its officers and of the Underwriters set forth in or made pursuant to this Agreement will remain in full force and effect, regardless of any investigation made by or on behalf of any Underwriter or the Company or any of the officers, directors, employees, agents or controlling persons referred to in Section 8 hereof, and will survive delivery of and payment for the Securities. The provisions of Sections 7 and 8 hereof shall survive the termination or cancellation of this Agreement.

SECTION 12. Notices. All communications hereunder will be in writing and effective only on receipt, and, if sent to the Representatives, will be mailed, delivered or telefaxed to the Citigroup Global Markets Inc. General Counsel (fax no.: (212) 816-7912) and confirmed to the General Counsel, Citigroup Global Markets Inc., at 388 Greenwich Street, New York, New York, 10013, Attention: General Counsel; or, if sent to the Company, will be mailed, delivered or telefaxed to Equinix Inc. General Counsel (fax no.: (650) 513-7909) and confirmed to it at 301 Velocity Way, Foster City, California, 94404, Attention: General Counsel.

SECTION 13. Successors. This Agreement will inure to the benefit of and be binding upon the parties hereto and their respective successors and the officers, directors, employees, agents and controlling persons referred to in Section 8 hereof, and no other person will have any right or obligation hereunder.

SECTION 14. Applicable Law. This Agreement will be governed by and construed in accordance with the laws of the State of New York applicable to contracts made and to be performed within the State of New York.

SECTION 15. Counterparts. This Agreement may be signed in one or more counterparts, each of which shall constitute an original and all of which together shall constitute one and the same agreement.

SECTION 16. Headings. The section headings used herein are for convenience only and shall not affect the construction hereof.

SECTION 17. Definitions. The terms which follow, when used in this Agreement, shall have the meanings indicated.

“Act” shall mean the Securities Act of 1933, as amended, and the rules and regulations of the Commission promulgated thereunder.

“Basic Prospectus” shall mean the prospectus referred to in paragraph 1(a) above contained in the Registration Statement at the Effective Date including any Preliminary Final Prospectus.

“Business Day” shall mean any day other than a Saturday, a Sunday or a legal holiday or a day on which banking institutions or trust companies are authorized or obligated by law to close in New York City.

“Effective Date” shall mean each date and time that the Registration Statement, any post-effective amendment or amendments thereto and any Rule 462(b) Registration Statement became or become effective.

“Exchange Act” shall mean the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission promulgated thereunder.

“Execution Time” shall mean the date and time that this Agreement is executed and delivered by the parties hereto.

“Final Prospectus” shall mean the prospectus supplement relating to the Securities that was first filed pursuant to Rule 424(b) after the Execution Time, together with the Basic Prospectus.

“Preliminary Final Prospectus” shall mean any preliminary prospectus supplement to the Basic Prospectus which describes the Securities and the offering thereof and is used prior to filing of the Final Prospectus, together with the Basic Prospectus.

“Registration Statement” shall mean the registration statement referred to in paragraph 1(a) above, including exhibits and financial statements, as amended at the Execution Time (or, if not effective at the Execution Time, in the form in which it shall become effective) and, in the event any post-effective amendment thereto or any Rule 462(b) Registration Statement becomes effective prior to the Closing Date, shall also mean such registration statement as so amended or such Rule 462(b) Registration Statement, as the case may be.

“Rule 415”, “Rule 424” and “Rule 462” refer to such rules under the Act.

“Rule 462(b) Registration Statement” shall mean a registration statement and any amendments thereto filed pursuant to Rule 462(b) relating to the offering covered by the Registration Statement referred to in Section 1(a) hereof.

If the foregoing is in accordance with your understanding of our agreement, please sign and return to us the enclosed duplicate hereof, whereupon this letter and your acceptance shall represent a binding agreement among the Company and the several Underwriters.

Very truly yours,

EQUINIX, INC.

By:		/s/ BRANDI L. GALVIN

		Name: Brandi L. Galvin
		Title: General Counsel

This letter is being delivered to you in connection with the proposed Underwriting Agreement (the “Underwriting Agreement”), between Equinix, Inc., a Delaware corporation (the “Company”), and you as representative of a group of Underwriters named therein, relating to an underwritten public offering (the “Public Offering”) of Common Stock, $0.001 par value (the “Common Stock”), of the Company. One or more additional Underwriters or representatives of the group of Underwriters may be added in connection with the Public Offering.

In order to induce you and other Underwriters to enter into the Underwriting Agreement, the undersigned will not, without the prior written consent of Citigroup Global Markets Inc., offer, sell, contract to sell, pledge or otherwise dispose of (or enter into any transaction which is designed to, or might reasonably be expected to, result in the disposition (whether by actual disposition or effective economic disposition due to cash settlement or otherwise) by the undersigned or any affiliate of the undersigned or any person in privity with the undersigned or any affiliate of the undersigned) directly or indirectly, including the filing (or participation in the filing) of a registration statement with the Securities and Exchange Commission in respect of, or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Securities and Exchange Commission promulgated thereunder with respect to, any shares of capital stock of the Company or any securities convertible into, or exercisable or exchangeable for such capital stock, or publicly announce an intention to effect any such transaction, for a period of 90 days after the date of the Underwriting Agreement so long as a preliminary prospectus supplement is filed with the Securities and Exchange Commission on or prior to November 7, 2003, other than shares of Common Stock disposed of as bona fide gifts approved by Citigroup Global Markets Inc.

If for any reason the Underwriting Agreement shall be terminated prior to the Closing Date (as defined in the Underwriting Agreement), the agreement set forth above shall likewise be terminated.

Yours very truly,

___________________________________________

Signature

Name: _____________________________________

Title: ______________________________________

		CITIGROUP GLOBAL MARKETS INC.

By:		/s/ JONATHAN MAUCK
		Name: Jonathan Mauck
		Title: Vice President

		SG COWEN SECURITIES CORPORATION

By:		/s/ WILLIAM B. BUCHANAN, JR.
		Name: William B. Buchanan, Jr.
		Title: Managing Director


Registration Statement No.		333-109697

Representatives		Citigroup Global Markets Inc. SG Cowen Securities Corporation

Title, Purchase Price and Description of Securities:

Title		Common Stock, $0.001 par value.

Number of Securities to be sold by the Company		4,500,000

Price to Public per Share (include accrued dividends, if any)		$20.00

Price to Public — Total		$90,000,000

Underwriting Discount per Share		$1.1120

Underwriting Discount — Total		$5,004,000

Proceeds to Company per Share		$18.888

Proceeds to Company — Total		$84,996,000

Closing Date, Time and Location		November 21, 2003 at 10:00 a.m. at Cahill Gordon & Reindel LLP, Eighty Pine Street, New York, New York

Type of Offering		Non-Delayed

Date referred to in Section 5(f) after which the Company may offer or sell securities issued or guaranteed by the Company without the consent of the Representative(s)		February 16, 2004

Underwriter	Number of Underwritten Securities to be Purchased	Number of Option Securities to be Purchased if Maximum Option Exercised
Citigroup Global Markets Inc.	2,452,500	367,875
SG Cowen Securities Corporation	999,000	149,850
Needham & Company, Inc.	558,000	83,700
Adams, Harkness & Hill, Inc.	445,500	66,825
Kaufman Bros., L.P.	45,000	6,750

Total	4,500,000	675,000