<PAGE>
 
                                                            Exhibit 10.10 (b)(i)
                                        
                      ASSIGNMENT AND ASSUMPTION AGREEMENT


                                        
     AGREEMENT dated as of December 5, 1997, among ABN AMRO BANK N.V. (the
"Assignor"), BANK AUSTRIA AKTEINGESELLSCHAFT, New York Branch (the "Assignee"),
GALILEO INTERNATIONAL, INC. (the "Borrower") and MORGAN GUARANTY TRUST COMPANY
OF NEW YORK, as Agent (the 'Agent").

     WHEREAS, this Assignment and Assumption Agreement (the "Agreement") relates
to the 364-Day Credit Agreement dated as of July 23, 1997 among the Borrower,
the Assignor and the other Banks parties thereto, as Banks, the Letter of Credit
Issuing Banks parties thereto and the Agent (as amended from time to time, the
"Credit Agreement");

     WHEREAS, as provided under the Credit Agreement, the Assignor has a
Commitment to make Loans to the Borrower and participate in Letters of Credit in
an aggregate principal amount at any time outstanding not to exceed
$33,333,333.00;

     WHEREAS, Committed Loans made to the Borrower by the Assignor under the
Credit Agreement in the aggregate principal amount of $18,333,333,16 are
outstanding at the date hereof; and

     WHEREAS, the Assignor proposes to assign to the Assignee all of the rights
of the Assignor under the Credit Agreement in respect of a portion of its
Commitment thereunder in an amount equal to $16,666,666.50 (the "Assigned 
Amount) together with a corresponding portion of its outstanding Committed Loans
and Letter of Credit Liabilities, and the Assignee proposes to accept assignment
of such rights and assume the corresponding obligations from the Assignor on
such terms;

     NOW, THEREFORE, in consideration of the foregoing and the mutual agreements
contained herein, the parties hereto agree as follows:

     SECTION 1. Definitions.  All capitalized terms not otherwise defined herein
shall have the respective meanings set forth in the Credit Agreement.

     SECTION 2. Assignment.  The Assignor hereby assigns and sells to the
Assignee all of the rights of the Assignor under the Credit Agreement to the
extent of the Assigned Amount, and the Assignee hereby accepts such assignment
from the Assignor and assumes all of the obligations of the Assignor under the
Credit Agreement to the extent of the Assigned Amount, including the purchase
from the Assignor of the corresponding portion of the principal amount of the
Committed Loans and Letter of Credit Liabilities made by the Assignor
outstanding at the date hereof. Upon the execution and delivery hereof by the
Assignor, the Assignee, [the
<PAGE>
 
Borrower, the Agent] and the Issuing Banks and the payment of the amounts
specified in Section 3 required to be paid on the date hereof (i) the Assignee
shall, as of the date hereof, succeed to the rights and be obligated to perform
the obligations of a Bank under the Credit Agreement with a Commitment in an
amount equal to the Assigned Amount, and (ii) the Commitment of the Assignor
shall, as of the date hereof, be reduced by a like amount and the Assignor
released from its obligations under the Credit Agreement to the extent such
obligations have been assumed by the Assignee. The assignment provided for
herein shall be without recourse to the Assignor.

     SECTION 3. Payments. As consideration for the assignment and sale
contemplated in Section 2 hereof, the Assignee shall pay to the Assignor on the
date hereof in Federal funds the amount heretofore agreed between them.''' It is
understood that facility fees and/or letter of credit fees accrued to the date
hereof are for the account of the Assignor and such fees accruing from and
including the date hereof are for the account of the Assignee. Each of the
Assignor and the Assignee hereby agrees that if it receives any amount under the
Credit Agreement which is for the account of the other party hereto. it shall
receive the same for the account of such other party to the extent of such other
party's interest therein and shall promptly pay the same to such other party.

     SECTION 4. Consent of the Borrower the Agent and the Issuing Banks. This
Agreement is conditioned upon the consent of the Borrower, the Agent and the
Issuing Banks pursuant to Section 9.06(c) of the Credit Agreement. The execution
of this Agreement by the Borrower. the Agent and the Issuing Banks is evidence
of this consent. Pursuant to Section 9.06(c). the Borrower agrees to execute and
deliver a Note payable to the order of the Assignee to evidence the assignment
and assumption provided for herein.

     SECTION 5. Non-Reliance on Assignor.  The Assignor makes no representation
or warranty in connection with, and shall have no responsibility with respect
to, the solvency, financial condition, or statements of the Borrower, or the
validity and enforceability of the obligations of the Borrower in respect of the
Credit Agreement or any Note or Letter of Credit.  The Assignee acknowledges
that it has, independently and without reliance on the Assignor, and based on
such documents and information as it has deemed appropriate, made its own credit
analysis and decision to enter into this Agreement and will continue to be
responsible for making its own independent appraisal of the business, affairs
and financial condition of the Borrower.
 
      SECTION 6. Governing Law.  This Agreement shall be governed by and
construed in accordance with the laws of the State of New York.

      SECTION 7. Counterparts.  This Agreement may be signed in any number of
counterparts, each of which shall be an original, with the same effect as is the
signatures thereto and hereto were  upon the same instrument.

      IN WITNESS WHEREOF, the parties have caused this Agreement to be executed
and delivered by their duly authorized officers as of the date first above
written.
<PAGE>
ZZZZZZZZZZZZZZ 
                              ABN AMRO BANK N.V.


                              By:__________________
                                 Name:
                                 Title:

                              By:__________________
                                 Name:
                                 Title:


                              BANK AUSTRIA
                              AKTIENGESELLSCHAFT,
                              New York Branch

                              By:_________________
                                 Name:
                                 Title:

                              By:_________________
                                 Name:
                                 Title: