<PAGE>   1



                                                                   EXHIBIT 10.26

                                 AMENDMENT NO. 1

       AMENDMENT NO. 1, dated as of March 23, 1999 (this "AMENDMENT"), to the
First Amended and Restated Credit Agreement, dated as of February 19, 1999, by
and among Global Vacation Group, Inc., the Lenders party thereto and The Bank of
New York, as Administrative Agent (as amended, supplemented or otherwise
modified from time to time, the "CREDIT AGREEMENT").

                                    RECITALS

I. Capitalized terms used herein and not defined herein shall have the meanings
assigned to such terms in the Credit Agreement.

II. The Borrower has requested that the Administrative Agent agree to amend the
Credit Agreement upon the terms and conditions contained in this Amendment, and
the Administrative Agent is willing so to agree.

Accordingly, in consideration of the Recitals and the terms and conditions
hereinafter set forth, and for other good and valuable consideration, the
receipt and adequacy of which are hereby acknowledged, the Borrower and the
Administrative Agent hereby agree as follows:

1.     Section 1.1 of the Credit Agreement is amended as follows:

       (a)    The definition of the term "Available Other Investment Amount" is
              amended by substituting the words "First Restatement Date" for the
              words "Original Effective Date".

       (b)    The definition of the term "Existing Letters of Credit" is amended
              and restated in its entirety as follows:

                     ""EXISTING LETTERS OF CREDIT" means (i) with respect to the
                  Borrower and each Person that is a Subsidiary as of the First
                  Restatement Date, the letters of credit referred to in
                  Schedule 8.1 and existing as of the First Restatement Date and
                  (ii) with respect to each Person that becomes a Subsidiary
                  after the First Restatement Date, the letters of credit
                  referred to in the schedule delivered with respect to such
                  Person pursuant to Section 8.1(e) and existing as of the date
                  such Person becomes a Subsidiary."


<PAGE>   2

       (c)    The definition of the term "Existing Letter of Credit Exposure" is
              deleted in its entirety.

       (d)    The proviso contained in the definition of the term "Leverage
              Ratio" is amended and restated in its entirety as follows:

              "provided, however, that, notwithstanding anything to the contrary
              contained herein, for purposes of this definition, (a) Total Debt
              shall not include any Indebtedness in respect of standby letters
              of credit and (b) EBITDA shall be computed on a consistent basis
              to reflect Acquisitions and Dispositions made by the Borrower and
              the Subsidiaries during the Four Quarter Trailing Period as if
              they occurred at the beginning of the Four Quarter Trailing
              Period".

       (e)    The parenthetical contained in the definition of the term "Letter
              of Credit Commitment" is deleted in its entirety.

2.     Clause (ii) of Section 2.1(a) of the Credit Agreement is amended and
       restated in its entirety as follows: "(ii) the Aggregate Revolving
       Exposure would not exceed the Aggregate Revolving Commitment".

3.     Clause (B) of Section 2.4(b)(i) of the Credit Agreement is amended and
       restated in its entirety as follows: "(B) the excess of the Aggregate
       Revolving Exposure over the Aggregate Revolving Commitment as so reduced
       or terminated".

4.     Clause (ii) of Section 2.5(a) of the Credit Agreement is amended and
       restated in its entirety as follows: "(ii) the Aggregate Revolving
       Exposure would not exceed the Aggregate Revolving Commitment".

5.     Section 7.13 of the Credit Agreement is amended and restated in its
       entirety as follows:

              "SECTION 7.13. EXISTING LETTERS OF CREDIT

                   The Borrower shall cause all Existing Letters of Credit to
       expire or otherwise terminate no later than (i) with respect to the
       Borrower and each Person that is a Subsidiary as of the First Restatement
       Date, May 6, 1999 and (ii) with respect to each Person that becomes a
       Subsidiary after the First Restatement Date, the date that is twelve
       months after the date such Person becomes a Subsidiary."

6.     Section 8.1 of the Credit Agreement is amended as follows:


       (a)    Subsection (b) is amended and restated in its entirety as follows:

              "(b) Subject to Section 7.13, Indebtedness of the Borrower or any
       Person that is a Subsidiary as of the First Restatement Date in respect
       of any Existing Letters of Credit, but not any extensions, renewals or
       replacements of such Indebtedness, and other Indebtedness of the Borrower
       or such Person as set forth on Schedule 8.1 and existing as of the First
       Restatement Date, and any extensions, renewals and replacements of such
       other Indebtedness;"

       (b)    Subsection (e) is amended as follows: (A) clause (ii) is amended
              and restated Iin its entirety as follows: "(ii) subject to Section
              7.13, Indebtedness of any Person that becomes a Subsidiary after
              the Original Effective Date, provided that, with respect to each
              such Person that becomes a Subsidiary after the First Restatement
              Date, the Borrower shall have delivered to the Administrative
              Agent a schedule in all respects reasonably satisfactory to the
              Administrative Agent

<PAGE>   3

              setting forth, if any, the Existing Letters of Credit with respect
              to such Person" and (B) the following parenthetical is inserted
              immediately after the reference "8.1(e)" contained in clause
              (iii): "(other than Indebtedness in respect of Existing Letters of
              Credit)".

       (c)    Subsection (f) is amended by inserting the following parenthetical
              immediately after the words "unsecured Indebtedness": "(other than
              Indebtedness in respect of letters of credit)".

7.     Section 8.2(c) of the Credit Agreement is amended and restated in its
       entirety as follows:

              "(c) (i) any Lien existing on any fixed or capital assets
       acquired, constructed or improved by the Borrower or any Subsidiary or
       (ii) any Lien existing on any asset prior to the acquisition thereof by
       the Borrower or any Subsidiary or existing on any asset of any Person
       that becomes a Subsidiary after the Original Effective Date prior to the
       time such Person becomes a Subsidiary, provided that (A) such Liens
       secure Indebtedness permitted by Section 8.1(e), (B) such Liens shall not
       apply to any other assets of the Borrower or any Subsidiary (other than
       fixed assets that constitute fixtures thereon or accessions thereto), (C)
       with respect to Liens under clause (i) of this Section 8.2(c) only, the
       Indebtedness secured by such Liens does not exceed the cost of acquiring,
       constructing or improving such fixed or capital assets and (D) with
       respect to Liens under clause (ii) of this Section 8.2(c) only, such
       Liens shall be not be created in contemplation of or in connection wth
       the acquisition of such asset or the creation or acquisition of such
       Person, as the case may be, and such Liens shall secure only those
       obligations that it secures on the date of such acquisition or creation,
       as the case may be, and, to the extent permitted under Section 8.1(e),
       any extensions, renewals and replacements thereof that do not increase
       the principal amount thereof .".

8.     Section 8.5 of the Credit Agreement is amended as follows: (a) clause (d)
       is amended by inserting the words "occurring after the First Restatement
       Date" immediately after the word "quarters" and (b) clause (e) is amended
       by substituting the words "as soon as practicable, but in no event less
       than five" for the words "not less than ten".

9.     Paragraphs 1 - 8 hereof shall not be effective until such time as the
       Required Lenders shall have consented hereto in writing.

10.    The Borrower hereby reaffirms and admits the validity and enforceability
       of each Loan Document and all of the obligations of each Loan Party under
       such Loan Document.


11.    In all other respects, the Loan Documents shall remain in full force and
       effect, and no amendment in respect of any term or condition of any Loan
       Document shall be deemed to be an amendment in respect of any other term
       or condition contained in any Loan Document.

12.    This Amendment may be executed in any number of counterparts all of
       which, when taken together, shall constitute one agreement. In making
       proof of this Amendment, it shall only be necessary to produce the
       counterpart executed and delivered by the party to be charged.

13.    THIS AMENDMENT IS BEING EXECUTED AND DELIVERED IN, AND IS INTENDED TO BE
       PERFORMED IN, THE STATE OF NEW YORK AND SHALL BE CONSTRUED AND
       ENFORCEABLE IN ACCORDANCE WITH, AND BE GOVERNED BY, THE INTERNAL LAWS OF
       THE STATE OF NEW YORK, WITHOUT REGARD TO PRINCIPLES OF CONFLICT OF LAWS.


<PAGE>   4

AS EVIDENCE of the agreement by the parties hereto to the terms and conditions
herein contained, each such party has caused this Amendment to be executed on
its behalf.

                              GLOBAL VACATION GROUP, INC.

                              By:    /s/ WALTER S. BERMAN
                                  -----------------------------------------
                              Name:      Walter S. Berman
                                   ----------------------------------------
                              Title:     Executive Vice President and Chief
                                           Financial officer
                                    ---------------------------------------

                              THE BANK OF NEW YORK,
                              individually and as Administrative Agent

                              By:    /s/ ROBERT SANTORIELLO
                                  -----------------------------------------
                              Name:      Robert Santoriello
                                   ----------------------------------------
                              Title:     Assistant Vice President
                                    ---------------------------------------

                              BANK OF AMERICA, FSB

                              By:    /s/ BARBARA LEVY
                                  -----------------------------------------
                              Name:      Barbara Levy
                                   ----------------------------------------
                              Title:     Senior Vice President
                                    ---------------------------------------

                              FIRST UNION NATIONAL BANK

                              By:    /s/ GORGE GONZALEZ
                                  -----------------------------------------
                              Name:      Gorge Gonzalez
                                   ----------------------------------------
                              Title:     Senior Vice President
                                    ---------------------------------------


<PAGE>   5

AGREED TO:

SUNSHINE VACATIONS, INC.
GLOBAL VACATION MANAGEMENT COMPANY
HADDON HOLIDAYS, INC.
GLOBETROTTERS, INC.
CLASSIC CUSTOM VACATIONS
MTI VACATIONS, INC.
GVG FINANCE COMPANY

AS TO EACH OF THE FOREGOING

By:   /s/ WALTER S. BERMAN
   -----------------------------------
Name:     Walter S. Berman
     ---------------------------------
Title:    Executive Vice President and
            Chief Financial officer
      --------------------------------