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                                                                    Exhibit 10.1

                             First Amendment to the
                                Credit Agreement
                            Dated as of May 22, 2001
                            (this "First Amendment")


     Reference is hereby made to that certain Credit Agreement dated as of March
5, 2001 (the "Credit Agreement"), by and between Verizon Investments Inc., a
Delaware corporation (the "Lender") and Genuity Inc., a Delaware corporation
(the "Borrower" and together with the Lender, the "Parties").  Capitalized terms
used in this First Amendment and not otherwise defined have the meaning ascribed
to them in the Credit Agreement.

     WHEREAS, the Parties desire to make certain amendments and modifications to
the terms of the Credit Agreement and to enter into certain other agreements,
all as specified in this First Amendment.

     In consideration of the terms and conditions set forth in this First
Amendment, the Parties agree as follows:

1.  Facility.  The Parties hereby amend and modify the "Facility" section of the
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   Credit Agreement by deleting the reference to "$500,000,000 line of credit
   (the "Facility")" in its entirety and replacing it with the following:
   "$900,000,000 line of credit, provided, however, the line of credit available
   prior to May 31, 2001 shall not exceed $500,000,000 (the "Facility")."

2.  Commitment Period.  The Parties hereby amend and modify the "Commitment
    -----------------
    Period" section of the Credit Agreement by deleting the reference to "March
    8, 2001 to, but including, May 31, 2001 (the "Commitment Period")." in its
    entirety, and replacing it with the following: "March 8, 2001 to, but not
    including, December 31, 2001 (the "Commitment Period")."

3.  Maturity Date. The Parties hereby amend and modify the "Maturity Date"
    -------------
    section of the Credit Agreement by deleting the reference to "May 31, 2001
    (the "Maturity Date")." in its entirety, and replacing it with the
    following: "December 31, 2001 (the "Maturity Date")."

4.  Additional Covenants.
    --------------------

    (a)  The Parties hereby amend and modify the "Additional Covenants" section
         of the Credit Agreement by deleting the reference to "$500,000,000" in
         clause (a) thereof and replacing it with the following: "$900,000,000".

    (b)  The Parties hereby amend and modify the "Additional Covenants" section
         of the Credit Agreement by deleting the reference to "4:1" in clause
         (a) thereof and replacing it with the following: "2.22:1".

    (c)  The Parties hereby amend and modify the "Additional Covenants" section
         of the Credit Agreement by inserting the following sentence at the end
         of clause (b) thereof: "In the alternative, at Lender's request,
         Borrower shall direct the underwriter or underwriters who are selling
         such indebtedness to pay the proceeds from the sale of such
         indebtedness at the closing of such sale (i) first, to Lender in an
         amount equal to the lesser of all amounts then borrowed under the
         Facility and the total amount of such proceeds, and (ii) second, to
         Borrower in an amount equal to all remaining proceeds from the sale of
         the indebtedness."
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5.  Effectiveness.  This First Amendment shall become effective immediately upon
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    execution and delivery by Lender and the receipt by Lender of (a) a copy of
    this First Amendment duly executed and delivered by Borrower, (b) a duly
    executed Master Promissory Note evidencing the increase in the size and
    extension of the Commitment Period and Maturity Date of the Facility, and
    (c) copies of the documentation described under the "Documentation" section
    of the Credit Agreement as modified to reflect the increased size and
    extension of the Commitment Period and Maturity Date of the Facility.

6.  Miscellaneous.  This First Amendment shall inure to the benefit of and be
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    binding upon the Parties, their successors and assigns. This First Amendment
    may be executed in one or more counterparts, all of which shall be one and
    the same agreement. Irrespective of the place of performance, this First
    Amendment shall be construed, interpreted and enforced in accordance with
    the laws of the State of New York, without reference to its conflicts of law
    principles. This First Amendment constitutes the entire agreement between
    the parties with respect to the subject matter hereof and merges and
    supersedes all prior and contemporaneous oral and written communications
    with respect hereto; provided, however, that it is the intent of the parties
    that this First Amendment shall amend only the sections of the Credit
    Agreement specifically referred to herein. Except as otherwise specifically
    provided herein, all other sections of and Schedules and Exhibits to the
    Credit Agreement shall be unaffected hereby and shall remain in full force
    and effect according to their terms. The Credit Agreement and this First
    Amendment shall be read and construed as one document.

     In witness whereof, the Parties hereto have caused this First Amendment to
be executed by their respective officers thereunto duly authorized, as of the
date first above written.



                         GENUITY INC.



                         By:  /s/ W. Jack Reagan
                              --------------------------------
                         Name:  W. Jack Reagan
                         Title: Vice President and Treasurer



                         VERIZON INVESTMENTS INC.



                         By:  /s/ Janet M. Garrity
                              --------------------------------
                         Name:  Janet M. Garrity
                         Title: President and Treasurer