AMENDMENT NO. 1 TO THE CREDIT AND GUARANTY AGREEMENT AS OF JUNE 1, 2007

EXHIBIT 4.1

EXECUTION COPY

AMENDMENT NO. 1 TO CREDIT AND GUARANTY AGREEMENT (this “ Amendment ”) dated as of June 1, 2007, to the CREDIT AND GUARANTY AGREEMENT dated as of May 9, 2007 (as amended, supplemented or otherwise modified from time to time, the “ Credit Agreement ”), among GLOBAL CROSSING LIMITED, a company incorporated under the laws of Bermuda (the “ Borrower ”), certain subsidiaries of the Borrower, as guarantors, the LENDERS party thereto (the “ Lenders ”), GOLDMAN SACHS CREDIT PARTNERS L.P., as Administrative Agent (the “ Administrative Agent ”) and Collateral Agent (the “ Collateral Agent ”) and CREDIT SUISSE SECURITIES (USA) LLC, as Syndication Agent.

WHEREAS pursuant to the Credit Agreement, the Lenders have agreed to extend credit to the Borrower on the terms and subject to the conditions set forth therein;

WHEREAS the Borrower has requested that (a) the Tack-on Lenders (as defined below) make certain loans to the Borrower on the Amendment No. 1 Effective Date and (b) certain provisions of the Credit Agreement be amended as set forth herein; and

WHEREAS the undersigned Tack-on Lenders are willing to make the Tack-on Loans, and the undersigned Lenders are willing to amend such provisions of the Credit Agreement, in each case on the terms and subject to the conditions set forth herein.

NOW, THEREFORE, in consideration of the mutual agreements herein contained and other good and valuable consideration, the sufficiency and receipt of which are hereby acknowledged, and subject to the conditions set forth herein, the parties hereto hereby agree as follows:

SECTION 1. Defined Terms. Unless otherwise specified, capitalized terms used but not defined herein shall have the meanings assigned to such terms in the Credit Agreement. As used in this Amendment:

“Amendment No. 1 Effective Date” shall be a date specified by the Borrower (provided that such date shall be a date not later than June 1, 2007), as of which date all the conditions set forth or referred to in Section 19 hereof shall have been satisfied.

“Required Amendment No. 1 Lenders” means, collectively, (a) the Requisite Lenders (as such term is defined in the Credit Agreement prior to giving effect to this Amendment) and (b) the Tack-on Lenders.

“Tack-on Lender” means a Lender having a Tack-on Loan Commitment.

“Tack-on Loan Commitment” means, with respect to each Tack-on Lender, the commitment of such Tack-on Lender to make Tack-on Loans hereunder on the Amendment No. 1 Effective Date, expressed as an amount

representing the maximum aggregate principal amount of the Tack-on Loans to be made by such Tack-on Lender hereunder, as set forth on Schedule 1 hereto. The aggregate amount of the Tack-on Lenders’ Tack-on Loan Commitments is $100,000,000.

“Transactions” means (a) the transactions contemplated by this Amendment (including, without limitation, the borrowing of the Tack-on Loans and the use of the proceeds therefrom in accordance with Section 2.6 of the Credit Agreement (as amended hereby) and (b) the amendment and restatement of the Intercreditor Agreement (as such term is defined in the Credit Agreement prior to giving effect to this Amendment) occurring concurrently herewith.

SECTION 2. Commitment. Subject to the terms and conditions set forth herein, each Tack-on Lender agrees to make a Tack-on Loan to the Borrower on the Amendment No. 1 Effective Date in a principal amount not exceeding such Tack-on Lender’s Tack-on Loan Commitment. The funding of the Tack-on Loans on the Amendment No. 1 Effective Date shall be consummated at a closing to be held on the Amendment No. 1 Effective Date at the offices of Cravath, Swaine & Moore LLP or at such other place as the Borrower and the Administrative Agent shall agree. Unless previously terminated, the Tack-on Loan Commitments shall terminate upon the making of the Tack-on Loans pursuant to this Amendment or, if earlier, 5:00 p.m., New York City time, on June 1 2007.

SECTION 3. Amendments to Section 1.1. (a) Section 1.1 of the Credit Agreement is hereby amended by adding the following definitions in the appropriate alphabetical order:

“Amendment No. 1” means Amendment No. 1 to Credit and Guaranty Agreement dated as of June 1, 2007, among the Borrower, each Guarantor Subsidiary, the Lenders party thereto, the Administrative Agent, the Collateral Agent and the Syndication Agent.

“Amendment No. 1 Effective Date” shall have the meaning set forth in Amendment No. 1.

“Existing Term Commitment” means, with respect to each Lender, the commitment, if any, of such Lender to make an Existing Term Loan hereunder on the Closing Date, expressed as an amount representing the maximum principal amount of the Existing Term Loans made by such Lender hereunder. For purposes of clarity, the Existing Term Commitments terminated on the Closing Date pursuant to Section 2.1(a).

“Existing Term Loans” means the Tranche B Term Loans made to the Borrower on the Closing Date pursuant to Section 2.1(a) and outstanding on the Amendment No. 1 Effective Date.

“Permitted De Minimis Dissolution” means a voluntary dissolution, reorganization, liquidation or similar action taken at the

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direction of the Borrower in respect of any Subsidiary of the Borrower; provided that (x) the fair market value of the assets owned directly or indirectly by such Subsidiary (as determined as of the time of purported dissolution, reorganization or liquidation by the Administrative Agent in its reasonable discretion and in consultation with the Borrower) shall not exceed $2,000,000 and (y) such Subsidiary does not otherwise qualify as a “significant subsidiary” under Article 1, Rule 1-02 of Regulation S-X promulgated under the Securities Act.

“Preferred Shares” means the 2.0% Cumulative Senior Convertible Preferred Shares, par value $0.10 per share, issued to STT and/or its Affiliates under the Certificate of Designation dated as of December 9, 2003 by the Borrower.

“Tack-on Loan” means a Loan made on the Amendment No. 1 Effective Date pursuant to Amendment No. 1.

“Tack-on Loan Commitment” shall have the meaning set forth in Amendment No. 1.

(b) The definition of the term “Applicable Margin” in Section 1.1 of the Credit Agreement is hereby amended by deleting such definition in its entirety and replacing it with the following:

“Applicable Margin” means (i) with respect to Eurodollar Rate Loans, 6.25% per annum and (ii) with respect to Base Rate Loans, 5.25% per annum.

(c) The definition of the term “Consolidated Reported EBITDA” in Section 1.1 of the Credit Agreement is hereby amended by deleting such definition in its entirety and replacing it with the following:

“ Consolidated Reported EBITDA ” means, for any period, an amount determined for Borrower and its Subsidiaries on a consolidated basis equal to (i) Consolidated Net Income for such period, plus , to the extent reducing Consolidated Net Income for such period, the sum, without duplication, of amounts for (a) consolidated interest expense, (b) provisions for taxes based on income, (c) total depreciation expense, (d) total amortization expense, (e) non-cash compensation expense from the issuance of stock-based awards, (f) net loss from discontinued operations, (g) losses in respect of Currency Agreements and other currency transactions entered into in the ordinary course of business and (h) other non-recurring or unusual losses or expenses for such period (including one-time out-of-pocket expenses related to the Impsat Acquisition, as determined by the Borrower in good faith and approved by the Administrative Agent in its reasonable discretion), minus , (ii) to the extent increasing Consolidated Net Income for such period, (a) net income

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from discontinued operations, (b) gains in respect of Currency Agreements and other currency transactions entered into in the ordinary course of business and, (c) interest income and (d) non-recurring or unusual gains for such period (as determined by the Borrower in good faith and approved by the Administrative Agent in its reasonable discretion).

(d) The definition of the term “Consolidated Total Debt” in Section 1.1 of the Credit Agreement is hereby amended by deleting the words “stated balance sheet” from such definition.

(e) The definition of the term “Intercreditor Agreement” in Section 1.1 of the Credit Agreement is hereby deleted in its entirety and replaced with the following text:

“Intercreditor Agreement” means the intercreditor agreement dated as of May 9, 2007, between the Collateral Agent, STT and Wells Fargo Bank, National Association, as trustee for the holders of the Mandatory Convertible Notes, substantially in the form attached as Exhibit M hereto, as amended, supplemented, modified or restated from time to time (including the amendment and restatement thereof effective as of the Amendment No. 1 Effective Date).

(f) The definition of the term “Post-Closing Collateral Requirement” in Section 1.1 of the Credit Agreement is hereby amended by replacing the text “Real Property” appearing in the proviso thereto with “Real Estate Asset”.

(g) The definition of the term “Lenders” in Section 1.1 of the Credit Agreement is hereby amended by inserting the text “each person listed on Schedule 1 to Amendment No. 1” immediately prior to the first occurrence of the word “and”.

(h) The definition of the term “Tranche B Term Loan Commitment” in Section 1.1 of the Credit Agreement is hereby deleted in its entirety and replaced with the following text:

“Tranche B Term Loan Commitment” means, with respect to any Lender, such Lender’s Existing Term Commitment or Tack-on Term Commitment”.

(i) The definition of the term “Tranche B Term Loan” in Section 1.1 of the Credit Agreement is hereby deleted in its entirety and replaced with the following text:

“Tranche B Term Loan” means an Existing Term Loan or a Tack-on Loan.

SECTION 4. Amendment to Section 2.1. Section 2.1 of the Credit Agreement is hereby amended and restated as follows:

(a) Loan Commitments . On the Closing Date, the Borrower borrowed the Existing Term Loans and all Existing Term Commitments terminated. Subject to the terms and conditions hereof, each Tack-on Lender severally agrees to make, on the Amendment No. 1 Effective Date, a Tack-on Loan to Borrower in an amount equal to such Lender’s Tack-on Loan Commitment.

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Borrower may make only one borrowing under the Tack-on Loan Commitment which shall be on the Amendment No. 1 Effective Date. Any Tranche B Term Loan repaid or prepaid may not be reborrowed. Subject to Sections 2.13(a) and 2.14, all amounts owed hereunder with respect to the Tranche B Term Loans shall be paid in full no later than the Maturity Date. Each Lender’s Tack-on Loan Commitment shall terminate immediately and without further action on the Amendment No. 1 Effective Date after giving effect to the funding of such Lender’s Tack-on Loan Commitment on such date.

(b) Borrowing Mechanics for Tack-on Loans .

(i) Borrower shall deliver to Administrative Agent a fully executed Funding Notice no later than one day prior to the Amendment No. 1 Effective Date. Promptly upon receipt by Administrative Agent of such Funding Notice, Administrative Agent shall notify each Tack-on Lender of the proposed borrowing.

(ii) Each Tack-on Lender shall make its Tack-on Loan available to Administrative Agent not later than 12:00 p.m. (New York City time) on the Amendment No. 1 Effective Date, by wire transfer of same day funds in Dollars, at the Principal office designated by Administrative Agent. Upon satisfaction or waiver of the conditions precedent specified herein, Administrative Agent shall make the proceeds of the Tack-on Loans available to Borrower on the Amendment No. 1 Effective Date by causing an amount of same day funds in Dollars equal to the proceeds of all such Loans received by Administrative Agent from Tack-on Lenders to be credited to the account of Borrower at the Principal Office designated by Administrative Agent or to such other account as may be designated in writing to Administrative Agent by Borrower.

SECTION 5. Amendment to Section 2.6. Section 2.6 of the Credit Agreement is hereby amended by (a) inserting the text “Existing” immediately prior to the text “Term Loans” in such Section and (b) inserting the following text immediately after the end of the first sentence in such Section:

“The proceeds of the Tack-on Loans will be used for working capital and general corporate purposes of Borrower and its Subsidiaries”.

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SECTION 6. Amendment to Section 2.13. Section 2.13(c) of the Credit Agreement is hereby amended by replacing each occurrence of “Closing Date” with the text “Amendment No. 1 Effective Date.”

SECTION 7. Amendment to Section 2.14. (a)  Section 2.14(c) of the Credit Agreement is hereby amended by deleting the text “On the fifth Business day immediately following the date on which a Change of Control shall occur,” and replacing it with the text “Immediately upon the occurrence of a Change of Control,”; and

(b) Section 2.14(d) is hereby amended by replacing the word “fifth” with the word “first” therein.

SECTION 8. Amendment to Section 2.15. Section 2.15(a) of the Credit Agreement is hereby amended by inserting the following text at the end of such Section:

“The Borrower shall select Tranche B Term Loans to be prepaid so that the aggregate amount of such prepayment is allocated among the Existing Term Loans and the Tack-on Loans pro rata based on the aggregate principal amount of outstanding Existing Term Loans and Tack-on Loans, respectively.”

SECTION 9. Amendment to Section 4.2. Section 4.2 of the Credit Agreement is hereby amended by inserting the following at the end of the last sentence of such Section:

“, indicating in each case whether such Subsidiary (x) is of the type described in clauses (i), (ii) and (iii) of the definition of “Excluded Subsidiary” as of the Amendment No. 1 Effective Date, (y) is a Required Closing Date Guarantor as of the Amendment No. 1 Effective Date, or (z) is not of the type described in either the preceding clauses (x) or (y).

SECTION 10. Amendment to Section 5.13. Section 5.13 of the Credit Agreement is hereby amended by replacing the words “the date of this Agreement” with “the Amendment No. 1 Effective Date.”

SECTION 11. Amendment to Section 6.2. Section 6.2(m) of the Credit Agreement is hereby amended by deleting the text “purchase money” from such Section.

SECTION 12. Amendment to Section 6.4. Section 6.4 of the Credit Agreement is hereby amended by inserting the following text immediately following clause (iii) thereof, and by renumbering the existing clause (iv) as clause (vi):

“(iv) Borrower may make Restricted Junior Payments to STT and its Affiliates as reimbursement for out-of-pocket costs and fees required to be paid in connection with any amendments, modifications, waivers or consents of any Preferred Shares or Warrants (as defined in the Recapitalization Agreement); provided that the amount of such payments shall not exceed (x) $1,000,000 in any Fiscal Year, with unused amounts rolling forward and cumulatively available for fees that exceed

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$1,000,000 in any Fiscal Year, and (y) $4,000,000 in the aggregate, (v) Borrower may make Restricted Junior Payments to STT and its Affiliates as reimbursement for actual and reasonable out-of-pocket expenses required to be paid in connection with any amendments, modifications, waivers or consents of any Preferred Shares or Warrants (as defined in the Recapitalization Agreement);”

SECTION 13. Amendments to Section 6.7. Sections 6.7(b) and 6.7(c) of the Credit Agreement are hereby amended by deleting each in its entirety and replacing them with the following:

(b) Liquidity . Borrower shall not at any time (i) prior to the delivery of the Compliance Certificate with respect to the Fiscal Quarter ended June 30, 2008, permit the aggregate amount of Unrestricted Cash and Cash Equivalents to be an amount less than $75,000,000, and (ii) thereafter permit the aggregate amount of Unrestricted Cash and Cash Equivalents to be an amount less than $50,000,000.

(c) Leverage Ratio . Borrower shall not permit the Leverage Ratio as of the last day of any Fiscal Quarter, beginning with the Fiscal Quarter ending June 30, 2008, to exceed the correlative ratio indicated:

SECTION 14. Amendment to Section 6.8. Section 6.8 of the Credit Agreement is hereby amended by (i) deleting the word “and” from Section 6.8(d), (ii) replacing the symbol “.” in Section 6.8(e) with the text “; and” and (iii) inserting the following text immediately following Section 6.8(e):

(f) Permitted De Minimis Dissolutions; provided that the aggregate fair market value of the assets of all Subsidiaries dissolved, reorganized or liquidated in reliance upon this Section 6.8(f) (as determined in accordance with the definition of “Permitted De Minimis Dissolution”) shall not exceed (x) $8,000,000 in any Fiscal Year and (y) $15,000,000 in the aggregate.

SECTION 15. Amendment to Section 6.11. Section 6.11 of the Credit Agreement is hereby amended by (i) replacing the parenthetical “(or similar governing body)” with the text “(or similar governing body, including any sub-committees or any executive committees thereof)” in Section 6.11(b), and (ii) replacing the words “Closing Date” with “Amendment No. 1 Effective Date” in Section 6.11(f).

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SECTION 16. Amendment to Section 8.1. Section 8.1(n) of the Credit Agreement is hereby amended by replacing the words “Closing Date” with “Amendment No. 1 Effective Date.”

SECTION 17. Other Amendments. (a)  Sections 2.8(b), 10.6(c) and 10.6(d) of the Credit Agreement shall each be hereby amended by replacing each occurrence of “Term Loan” and/or “Term Loans” with “Loan” and/or “Loans”, as applicable, in each such Section;

(b) Section 5.10 of the Credit Agreement is hereby amended by (i) inserting the text “, unless not required pursuant to clause (b) of this Section 5.10” immediately following the first occurrence of the word “and” in clause (a) thereof and (ii) inserting the text “other than with respect to assets as to which the Administrative Agent, in its reasonable discretion, shall have determined that the cost of obtaining such security interest is excessive in relation to the benefit to the Lenders provided thereby” at the beginning of clause (b) thereof;

(c) Section 5.13 of the Credit Agreement is hereby amended by (i) inserting the text “or Guaranty” immediately following the first occurrence of the word “assets” in the first parenthetical thereof and (ii) inserting the letter “s” after the word “Lender” in such parententhetical.

(d) Each of Sections 7.11(a), 8.1(g) and 8.1(i) is hereby amended by inserting the text “Other than pursuant to a Permitted De Minimis Dissolution,” at the beginning thereof;

(e) Annex H of the Credit Agreement is hereby amended and restated in its entirety in the form attached hereto as Exhibit C; and

(f) Schedule 4.2 of the Credit Agreement shall be replaced with the revised Schedule 4.2 attached as Exhibit D to this Agreement.

SECTION 18. Representations and Warranties. Each Credit Party represents and warrants to the Administrative Agent and to each of the Lenders that:

(a) This Amendment has been duly authorized, executed and delivered by it and constitutes a legal, valid and binding obligation of the Borrower and each Subsidiary Guarantor, enforceable against each of them in accordance with its terms, subject to applicable bankruptcy, insolvency, reorganization, moratorium or other laws affecting creditors’ rights generally and subject to general principles of equity, regardless of whether considered in a proceeding in equity or at law.

(b) The representations and warranties of each Credit Party set forth in the Credit Documents (i) that are qualified as to materiality or Material Adverse Effect are true and correct and (ii) that are not so qualified are true and correct in all material respects, in each case on and as of the Amendment No. 1 Effective Date (other than with respect to any representation and warranty that expressly relates to an earlier date, in which case such representation and warranty is true and correct, or true and correct in all material respects, as the case may be, as of such earlier date).

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(c) At the time of and immediately after giving effect to this Amendment, no Default or Event of Default shall have occurred and be continuing.

SECTION 19. Conditions. The obligations of the Tack-on Lenders to fund the Tack-on Loans hereunder shall not become effective until the date on which each of the following conditions is satisfied:

(a) The Administrative Agent shall have received from the Borrower, no later than one day prior to the Amendment No. 1 Effective Date, a fully executed Funding Notice with respect to the borrowing of the Tack-on Loans.

(b) The Administrative Agent shall have received a favorable written opinion (addressed to the Administrative Agent and the Lenders and dated as of the Amendment No. 1 Effective Date) of (i) Mitchell Sussis, internal counsel for the Borrower and its Subsidiaries in form and substance reasonably satisfactory to the Administrative Agent and substantially in the form of Exhibit A-1 hereto, (ii) Latham & Watkins LLP, counsel for the Borrower and its Subsidiaries in form and substance reasonably satisfactory to the Administrative Agent and substantially in the form of Exhibit A-2 hereto, (iii) Appleby, Bermuda counsel for the Borrower and its Subsidiaries, in form and substance reasonably satisfactory to the Administrative Agent and substantially in the form of Exhibit A-3 hereto, (iv) Latham & Watkins, UK counsel for the Borrower and its Subsidiaries, in form and substance reasonably satisfactory to the Administrative Agent and substantially in the form of Exhibit A-4 hereto, (v) Weil, Gotshal & Manges LLP, counsel for the Borrower and it Subsidiaries, in form and substance reasonably satisfactory to the Administrative Agent and substantially in the form of Exhibit A-5 hereto, (vi) Houthoff Buruma N.V., Netherlands counsel for the Borrower and its Subsidiaries, in form and substance reasonably satisfactory to the Administrative Agent and substantially in the form of Exhibit A-6 hereto, (vii) Whyte Hirschboeck Dudek S.C., Wisconsin, Iowa and Michigan counsel to the Borrower and its Subsidiaries, in form and substance reasonably satisfactory to the Administrative Agent and substantially in the form of Exhibit A-7 hereto and (viii) Appleby, Mauritius counsel to STT, in form and substance reasonably satisfactory to the Administrative Agent and substantially in the form of Exhibit A-8 hereto, and in the case of each such opinion required by this paragraph, covering such other matters relating to the Credit Parties, the Credit Documents or the Transactions as the Administrative Agent shall reasonably request. The Borrower hereby requests such counsel to deliver such opinions.

(c) The Administrative Agent shall have received such documents and certificates as the Administrative Agent or its counsel may reasonably request relating to the organization, existence and good standing of each Credit Party, the authorization of this Amendment and any other legal matters relating to Credit Parties, the Credit Documents or the Transactions, all in form and substance reasonably satisfactory to the Administrative Agent and its counsel.

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(d) The Administrative Agent shall have received a certificate, dated the Amendment No. 1 Effective Date and signed by an Authorized Officer of the Borrower, confirming (x) that the representations and warranties set forth in Section 18 hereof are true and correct in all material respects and (y) compliance with the conditions set forth in paragraphs (a) and (b) of Section 3.2 of the Credit Agreement prior to and immediately after giving effect to the Transactions.

(e) The Administrative Agent shall have received all fees and other amounts due and payable by the Borrower or any other Credit Party to the Administrative Agent on or prior to the Amendment No. 1 Effective Date (including, to the extent invoiced and without limitation, (i) any out-of-pocket expenses of the Administrative Agent refer