<PAGE>   1
                                                                 EXHIBIT 10.27.1

                      CRICKET COMMUNICATIONS HOLDINGS INC.
                           CRICKET COMMUNICATIONS INC.
                           10307 PACIFIC CENTER COURT
                           SAN DIEGO, CALIFORNIA 92121


                                                   as of February 5, 2001

Ericsson Credit AB
Tefonvagen 30
Stockholm 126 25
Sweden
Attention:  President

                       Amendment No. 1 to Credit Agreement

Ladies and Gentlemen:

        We refer to Credit Agreement dated as of October 20, 2000, as amended
(the "Credit Agreement"), between you, as lender and administrative agent, and
us. Capitalized terms not otherwise defined in this Amendment have the
respective meanings specified in the Credit Agreement.

        You and we agree as follows:

        1.      The Credit Agreement is amended as follows

                (a) Section 4.03(c) is amended in its entirety to read as
                follows:

                "(c) At the time of and immediately after giving effect to such
                Borrowing, (i) either (A) the aggregate principal amount of all
                Loans made hereunder (whether or not repaid) shall not exceed
                (I) if such time is prior to December 31, 2001, [*] of the sum
                of the aggregate Purchase Price payments made to Ericsson
                Wireless at or prior to such time, plus [*], (II) if such time
                is on or after December 31, 2001 and prior to the second
                anniversary of the date of this Agreement, [*] of the sum of the
                aggregate Purchase Price payments made to Ericsson Wireless at
                or prior to such time, plus [*], and (III) otherwise [*] of the
                sum of the aggregate Purchase Price payments made to Ericsson
                Wireless at or prior to such time or (B) the proceeds of such
                Borrowing are being used solely to pay all or any portion of the
                Purchase Price theretofore unpaid, (ii) the ratio of Total
                Indebtedness to Total Contributed Capital shall not exceed 2.0
                to 1.0 and (iii) the aggregate principal amount of all Eligible



[*] CERTAIN MATERIAL (INDICATED BY AN ASTERISK) HAS BEEN OMITTED FROM THIS
DOCUMENT PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED MATERIAL
HAS BEEN FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION.

<PAGE>   2

                Secured Debt described in clauses (a), (b) and (c) of the
                definition of "Eligible Secured Debt" that has been incurred (on
                a cumulative basis, whether or not such Eligible Secured Debt
                remains outstanding) shall not exceed $1,845,000,000."

                (b) Section 5.10 is amended in its entirety to read as follows:

                        Section 5.10 Use of Proceeds. The proceeds of the Loans
                will be used (a) to make payments in respect of the Purchase
                Price and Permitted Third Party Payments and (b) to pay fees
                payable under Sections 2.10(a), 2.10(b) and 2.10(c), interest
                payable to Ericsson, the Agent or the Lenders under this
                Agreement and out-of-pocket expenses incurred in connection with
                the negotiation, execution and delivery of the Loan Documents;
                provided, however, that (i) the equipment, goods and/or services
                financed with or constituting Permitted Third Party Payments
                shall be used solely in the markets which are generally
                utilizing equipment provided by Ericsson Wireless (as opposed to
                markets which are generally utilizing equipment provided by
                Lucent, Nortel or other competitors of Ericsson Wireless), (ii)
                proceeds of Loans shall not be used to purchase an FCC License
                as referred to in clause (b) of the definition of "Permitted
                Third Party Payments" unless such FCC License is for a market
                that is to generally utilize equipment provided by Ericsson
                Wireless (as opposed to a market that is to generally utilize
                equipment provided by competitors of Ericsson Wireless) and
                (iii) to the extent that after giving effect to any Loan on any
                date the aggregate principal amount of the Loans would exceed
                [*] of the sum of the aggregate Purchase Price payments made to
                Ericsson Wireless at or prior to such time, plus [*], such
                excess shall be used or shall have been used only for the
                purpose of purchasing FCC Licenses.

        2. This Amendment shall become effective as of the date first-above
written when (a) executed by you and delivered to us and when you shall have
received counterparts of this Amendment, (b) the consent attached hereto duly
executed by each signatory thereto and (c) an amendment to the Purchase
Agreement referred to in the commitment letter dated as of January 11, 2001
between the Borrower and you shall have been duly executed and delivered by the
parties to the Purchase Agreement. This Amendment shall terminate without coming
into effect unless the conditions specified in the preceding sentence shall have
been satisfied prior to February 15, 2001.

        3. Each of us represents and warrants to you as follows:

                (a) It is duly organized and validly existing under its
        jurisdiction of organization, with all requisite power and authority,
        corporate and otherwise, to execute, deliver and perform this Amendment
        and the transactions contemplated hereby.



[*] CERTAIN MATERIAL (INDICATED BY AN ASTERISK) HAS BEEN OMITTED FROM THIS
DOCUMENT PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED MATERIAL
HAS BEEN FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION.

<PAGE>   3

                (b) The execution, delivery and performance by it of this
        Amendment and the transactions contemplated hereby have been validly
        authorized by all requisite action.

                (c) The execution, delivery and performance of this Amendment by
        it do not and will not violate any applicable law, rule, regulation,
        judgment, order or agreement with any third party.

                (d) This Amendment constitutes its valid and binding obligation,
        enforceable against it in accordance with its terms.

        4. On and after the effectiveness of this Amendment, each reference in
the Credit Agreement to "this Agreement", "hereunder", "hereof" or words of like
import referring to the Credit Agreement, and each reference in each of the
other Loan Documents to "the Credit Agreement", "thereunder", "thereof" or words
of like import referring to the Credit Agreement, shall mean and be a reference
to the Credit Agreement, as amended by this Amendment.

        5. The Credit Agreement and each of the other Loan Documents, as
specifically amended by this Amendment, are and shall continue to be in full
force and effect and are hereby in all respects ratified and confirmed. Without
limiting the generality of the foregoing, the Security Documents and all of the
Collateral described therein do and shall continue to secure the payment of all
Obligations of the Borrower. The execution, delivery and effectiveness of this
Amendment shall not, except as expressly provided herein, operate as a waiver of
any right, power or remedy of any Lender or the Administrative Agent under the
Credit Agreement or any of the other Loan Documents, nor constitute a waiver of
any provision of the Credit Agreement or any of the other Loan Documents.

        6. Cricket Communications Holdings Inc. consents to this Amendment and
confirms and agrees that notwithstanding the effectiveness of this Amendment,
the Guarantee Agreement is, and shall continue to be, in full force and effect
and is hereby ratified and confirmed in all respects, except that, on and after
the effectiveness of this Amendment, each reference in the Guarantee Agreement
to the Credit Agreement, directly, by words of like import or by words that
incorporate the Credit Agreement among the documents referred to, shall mean and
be a reference to the Credit Agreement, as amended by such Amendment.

        7. This Amendment may be executed in any number of counterparts and by
different parties hereto in separate counterparts, each of which when so
executed shall be deemed to be an original and all of which taken together shall
constitute one and the same agreement. Delivery of an executed counterpart of a
signature page to this Amendment by telecopier shall be effective as delivery of
a manually executed counterpart of this Amendment.

        8. This Amendment shall be governed by, and construed in accordance
with, the laws of the State of New York.



<PAGE>   4

        If you agree to the terms and provisions hereof, please evidence such
agreement by executing and returning a counterpart of this Amendment to us.

                                            Very truly yours,

CRICKET COMMUNICATIONS HOLDINGS INC.        CRICKET COMMUNICATIONS INC.



By /s/ TOM WILLARDSON                       By /s/ TOM WILLARDSON
   -------------------------------             ---------------------------------
   Title                                       Title


Agreed as of the date first-above written.

ERICSSON CREDIT AB, as Administrative Agent and Lender



By      /s/ OSSIE EVERUM
   -------------------------------
   Title    OSSIE EVERUM



                                     CONSENT

                THE UNDERSIGNED, as of the date of the foregoing Amendment,
consents to such Amendment and confirms and agrees that notwithstanding the
effectiveness of such Amendment, the Parent Guarantee is, and shall continue to
be, in full force and effect and is hereby ratified and confirmed in all
respects, except that, on and after the effectiveness of such Amendment, each
reference in the Parent Guarantee to the Credit Agreement, directly, by words of
like import or by words that incorporate the Credit Agreement among the
documents referred to, shall mean and be a reference to the Credit Agreement, as
amended by such Amendment.

                                            LEAP WIRELESS INTERNATIONAL INC.



                                            By /s/ TOM WILLARDSON
                                               ---------------------------------
                                               Title