<PAGE>

                                                                   EXHIBIT 10.28

                                    WORLDSPAN

                            ASSOCIATE PARTICIPATION
                       GLOBAL REFERENCE SYSTEM AGREEMENT

     THIS WORLDSPAN Associate Participation Agreement ("Agreement") is effective
     this 2nd day of August, 1999, between WORLDSPAN, L.P., having its principal
     place of business at 300 Galleria Parkway, N.W., Suite 2100, Atlanta,
     Georgia 30339 ("WORLDSPAN"). and Orbit Network Inc. ("Associate"), having
     its principal place of business at 505A San Marin Drive, Suite 300, Novato,
     CA 94945.

     WHEREAS, WORLDSPAN is a computer reservation system vendor providing access
to its WORLDSPAN System to travel agencies and others in the travel industry.

     WHEREAS, Associate operates and/or markets products, goods or services to
the travel industry.

     WHEREAS,WORLDSPAN is prepared to provide Associate access to WORLDSPAN's
Global Reference System ("GRS"), a static informational display capable of
storing information and other marketing opportunities.

     WHEREAS, Associate desires to provide information to WORLDSPAN users
through the GRS and other marketing opportunities.

     NOW THEREFORE, it is agreed:

     1.   DEFINITIQNS
          -----------

          The capitalized terms used in this Agreement and any supplement or
          addendum to this Agreement shall have the meanings described below:

          AccessPLUS- Shall mean supplemental services provided by WORLDSPAN to
          ----------
          permit enhanced connectivity between the WORLDSPAN CRS and Associate
          System.

          ARINC - Shall mean Aeronautical Radio, Inc.
          -----

          Associate System - Shall mean Associate's automated reservation
          -----------------
          system.

          Confidential Information - Shall mean proprietary information, data,
          -------------------------
          drawings, specifications. documentation, manuals, plans, and other
          materials marked as "Confidential", "Sensitive" or "Proprietary",
          except, (i) information known to the receiving party prior to
          disclosure, (ii) information developed by the receiving party
          independent of any confidential materials provided by the disclosing
          party, or (iii) information which is publicly known or publicly
          available in the relevant trade or industry.

          CRS - Shall mean a computerized reservation system as used by travel
          ----
          agents and other entities that market or sell travel related products
          and services to collect store, process, display and distribute
          information concerning air and ground transportation, lodging and
          other travel related goods and services, and enable users to: (i)
          inquire about, reserve or otherwise confirm the availability of such
          goods and service; and/or (ii) issue tickets to permit the purchase or
          use of such goods and services.

                                       1
<PAGE>

          GRS -Shall mean Global Reference System, a static display contained in
          ---
          the WORLDSPAN System which Associate may use to communicate
          information to WORLDSPAN Users (sometimes referred to as "Direct
          Reference System DRS").

          IATA - Shall mean the International Air Transport Association.
          ----

          Product - Shall mean one or more of the products, goods or services
          -------
          operated or provided by Associate to WORLDSPAN Users pursuant to this
          Agreement as agreed to by the parties from time to time.

          PNR - Shall mean a passenger name record created by a WORLDSPAN User
          ----
          in the WORLDSPAN System.

          SITA - Shall mean Societe Internationale de Telecommunications
          ----
          Aeronautiques.

          WTS - Shall mean WORLDSPAN TRAVEL SUPPLIERS.
          ---

          WORLDSPAN User - Shall mean a person or entity which utilizes the
          --------------
          WORLDSPAN System, directly or indirectly to transact travel related
          business.

          WORLDSPAN System - Shall mean the CRS provided by WORLDSPAN on the
          ----------------
          date of this Agreement or in the future regardless of the facilities
          employed to permit access to such system.

     2.   RESPONSIBILITIES OF ASSOCIATE
          -----------------------------

          A.   Associate will, at its own cost, provide through Associate System
               its Product, and such other products or services as may be
               mutually agreed upon by the parties through the WORLDSPAN System
               in a uniform manner to all WORLDSPAN Users.  If Associate
               participates in other CRSs, Associate will provide products,
               services and service levels through the WORLDSPAN System to
               WORLDSPAN Users which are at least equal to those provided to any
               such other CRS and its user including, but not limited to, data
               bases, communications methods and methods of access to Associate
               System, except for methods not permitted due to technical
               limitations in the WORLDSPAN System.  If Associate participates
               in other CRSs, Associate shall pay WORLDSPAN fees comparable to
               those paid to any such other CRS.

          B.   Associate shall be responsible for all costs associated with the
               Product provided to WORLDSPAN Users, except for the initial
               system briefing to WORLDSPAN Users, which will be the
               responsibility of WORLDSPAN.

          C.   Associate shall ensure that the information provided through the
               GRS shall be in compliance with all local, state, and federal
               laws.

          D.   Associate shall not provide Products through GRS without prior
               written consent of WORLDSPAN.

          E.   Associate shall, via CRT entry or other mutually agreed upon
               facility, create and update as applicable GRS information in the
               WORLDSPAN System. The format of the Information contained in GRS
               shall be determined by WORLDSPAN. Associate shall, at a minimum,
               provide information to effectively communicate the Product to
               WORLDSPAN Users. Associate shall be responsible for, and assumes
               all liability with respect to, the entry, updating and accuracy
               of this information in GRS as well as information otherwise
               provided by Associate pursuant to this Agreement. Information
               entered into GRS which WORLDSPAN

                                       2
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               in its sole discretion determines to be inappropriate,
               misleading, or defamatory, may be deleted by WORLDSPAN from GRS,
               without liability, upon notice to Associate.  Associate shall at
               all times comply with WORLDSPAN's GRS keyword indexing scheme.

          F.   To permit Product information to be provided to WORLDSPAN Users,
               Associate will either: (1) lease from WORLDSPAN AT WORLDSPAN'S
               then current monthly charges, a sufficient number of WORLDSPAN
               terminals subject to the terms of a separate WORLDSPAN Equipment
               and Software Addendum; or (2) arrange for dial-in access to the
               WORLDSPAN System through WORLDSPAN licensed software programs and
               access agreements pursuant to the terms of a separate World Dial
               Link Addendum; or (3) secure WORLDSPAN's prior written approval
               and certification of Associate's own software and/or hardware to
               enable Associate to access the WORLDSPAN System; or (4) provide
               text documentation to WORLDSPAN and authorize WORLDSPAN to create
               and update GRS Information in the WORLDSPAN System as applicable,
               according to the designated WORLDSPAN fees for such services.

          G.   Associate shall cooperate with WORLDSPAN in efforts to improve
               the quantity and quality of all Products provided to WORLDSPAN
               Users, especially those related to the dissemination of more
               complete, accurate, and current data pertaining to the Products.
               Associate also agrees to assist WORLDSPAN in expanding and
               maintaining information concerning the Products in the WORLDSPAN
               System, including the direct updating of Associate data by
               Associate personnel through WORLDSPAN terminals and/or by other
               means as mutually agreed.

          H.   Associate agrees that it will not discriminate against or
               disfavor in any manner whatsoever any WORLDSPAN User on account
               of that User's selection, possession or use of the WORLDSPAN
               System.

          I.   Associate agrees promptly to pay WORLDSPAN all amounts due
               pursuant to this Agreement, and all agreements, supplements,
               addenda, schedules and exhibits now or hereafter completed
               pursuant to this Agreement, without deduction, set-off
               counterclaim.

          J.   The use of the WORLDSPAN international communications network is
               restricted to WORLDSPAN business by various international
               government regulations and agreements, and said network shall not
               be utilized by Associate to conduct any Third Party
               Communications Traffic. "Third Party Communications Traffic," for
               purposes of this subsection, includes the use of the WORLDSPAN
               international network to communicate with others in any manner,
               including but not limited to direct message transmission or
               depositing of information in the WORLDSPAN computer center for
               the purpose of communication with others, which communications do
               not pertain to WORLDSPAN business. WORLDSPAN shall have the right
               to terminate this Agreement in the event Associate contravenes
               the foregoing restrictions or WORLDSPAN is required by any
               governmental authority having jurisdiction thereof to cease
               handling Associates messages or communications, and WORLDSPAN
               shall not be liable for any damages of any nature whatsoever
               incurred by Associate due to such termination. Associate hereby
               releases, discharges and agrees to indemnify, defend and save
               harmless WORLDSPAN, its partners, affiliates, directors,
               officers, agents and employees from and against any and all
               claims or actions of any nature whatsoever arising out of or
               attributable to any such termination, including but not limited
               to any penalties or fines imposed upon WORLDSPAN as a result of
               such Third Party Communications Traffic.

                                       3
<PAGE>

          K.   Associate shall reasonably cooperate with WORLDSPAN to secure any
               governmental approvals or exemptions necessary to put this
               Agreement and any and all parts thereof into effect, and shall
               assist WORLDSPAN to maintain such approvals or exemptions once
               received.


3.        RESPONSIBILITIES OF WORLDSPAN
          -----------------------------

          A.   WORLDSPAN will provide WORLDSPAN Users with displays containing
               information regarding the Products.

          B.   WORLDSPAN is not required to verify the accuracy of the text of
               the GRS. Associate acknowledges and agrees that WORLDSPAN is not
               required to perform any verification of any sort of the text
               submitted to WORLDSPAN by Associate for input into the WORLDSPAN
               System and WORLDSPAN's function hereunder is solely to perform
               the services set forth within this Agreement. WORLDSPAN makes no
               representation whatsoever to Associate; or any third party, as to
               the accuracy or completeness of the text submitted by Associate
               for input by WORLDSPAN into the WORLDSPAN System.

          C.   WORLDSPAN retains the right to review all data pertaining to the
               information input into GRS and Associate agrees to provide
               WORLDSPAN, on request, all data pertaining to such information
               prior to input into the WORLDSPAN System. WORLDSPAN may, in its
               sole discretion, after review of the data, deny the input of such
               data into the WORLDSPAN System.

          D.   WORLDSPAN shall provide reasonable information to Associate to
               substantiate the charges to Associate pursuant to this Agreement.

          E.   WORLIDSPAN shall maintain one or more facilities for the purpose
               of responding to Associate's questions concerning the operation
               of, or any data within, the WORLDSPAN System.

          F.   WORLDSPAN retains the right to enhance or modify, in whole or in
               part, the WORLDSPAN System at its discretion. Any enhancement or
               modification of the WORLDSPAN System will be offered to all
               similar associates on a non-discriminatory basis; provided,
               however, technical, equipment or resource limitations may make it
               impratical or not feasible for WORLDSPAN to implement an
               enhancement or modification at the same time or in the exact same
               manner for all associates. In such case, WORLDSPAN will determine
               the order and nature of implementation among all of its
               associates in its sole discretion. The foregoing shall include,
               but is not limited to, the right of WORLDSPAN to migrate or
               include Associate, other WORLDSPAN associates and WORLDSPAN Users
               to any new WORLDSPAN System. Nothing herein shall be construed to
               require WORLDSPAN to develop or utilize any additional CRS.

          G.   At its own expense and discretion, WORLDSPAN may communicate with
               WORLDSPAN Users to draw attention to the availability of the GRS
               in the WORLDSPAN System, to encourage WORLDSPAN Users to refer to
               the GRS in the WORLDSPAN System and generally to promote GRS in
               the WORLDSPAN System.

                                       4
<PAGE>

          4.   TERM
               ----

               This Agreement shall become effective upon the date first written
               above and will continue thereafter for an initial period of one
               (1) year. Thereafter this Agreement will continue until
               terminated by either party at any time thereafter upon not less
               than thirty (30) days prior written notice to the other, or until
               otherwise terminated pursuant to this Agreement.

          5.   FEES
               ----

               A.   Associate shall pay Five Hundred Dollars ($500.00) per month
                    to WORLDSPAN for ten (10) pages of GRS. Additional pages may
                    be added at the rate of Twenty-Five Dollars ($25.00) per
                    page.

               B.   If Associate desires to have WORLDSPAN input the GRS data,
                    WORLDSPAN will do so at the rate of Thirty Dollars ($30.00)
                    per hour initial set up plus Twenty-Five Dollars ($25.00)
                    per hour for maintenance/updates.

               C.   WORLDSPAN shall submit monthly invoices covering the fees
                    earned hereunder for that month and such invoices shall be
                    due and payable by Associate within thirty (30) days of the
                    date of each such invoice. WORLDSPAN may impose a late
                    payment fee at the rate of one percent (1%) per month for
                    any amount more than fifteen (15) days overdue. All payments
                    shall be in U. S. currency.

               D.   Following the expiration of the initial period, fees charged
                    to Associate pursuant to this Agreement may be increased
                    upon not less than thirty (30) days prior written notice by
                    WORLDSPAN

               E.   WORLDSPAN reserves the right to charge for any service which
                    it currently provides without separate charge including, but
                    not limited to, additional GRS pages of future enhancements
                    regarding credit card authorization. The services, which
                    Associate receives without separate charge from time to time
                    shall be referred to as "Additional Services." In the event,
                    WORLDSPAN decides to separately charge for any Additional
                    Services, WORLDSPAN shall give not less than sixty (60) days
                    prior written notice to Associate of WORLDSPAN's decision to
                    charge for such services. If Associate elects not to
                    participate in such Additional Services, Associate shall
                    notify WORLDSPAN at least thirty (30) days prior to the
                    effective date of the separate charge for such Additional
                    Services, and WORLDSPAN shall have no obligation to provide
                    such Additional Services to Associate after such effective
                    date.

               F.   Any charge for any Additional Services hereinafter imposed
                    may be modified by WORLDSPAN at its discretion on not less
                    than thirty (30) days prior written notice. If Associate
                    elects not to participate any longer in the Additional
                    Services, then Associate shall notify WORLDSPAN of such
                    election at least ten (10) days prior to the effective date
                    of such modified change, and WORLDSPAN shall not be
                    obligated to provide such Additional Services to Associate
                    after such effective date.

     6.   OTHER SYSTEMS
          -------------

          Associate acknowledges that users of other third parties utilizing or
          marketing the WORLDSPAN System may be allowed access to information in
          the GRS.

                                       5
<PAGE>

     7.   TAXES
          -----

          In addition to any other charges set forth herein, Associate shall pay
          to WORLDSPAN or reimburse WORLDSPAN, as appropriate, for all sales,
          use, excise, property, or other similar taxes now or hereafter imposed
          by any federal, state or local taxing authority on amounts paid to
          WORLDSPAN by Associate. Notwithstanding the foregoing, Associate shall
          not, in any event, be responsible for any taxes payable on WORLDSPAN's
          net income or taxes in lieu of net income taxes, or for charges
          imposed on WORLDSPAN for the privilege of doing business.

     8.   IDEMNIFICATION
          -------------

          A.   Each party shall indemnify, defend and hold harmless the other
               party, its directors, affiliates, partners, officers, employees
               and agents, from all liabilities, damages, and expenses, and
               claims for damages, suits, proceedings, recoveries, judgments or
               executions (including but not limited to litigation costs,
               expenses, and reasonable attorneys' fees) arising out of or in
               connection with any claim that the use of the identifying party's
               system or data (including, without limitation, software) by the
               other party infringes any third party patent, copyright,
               trademark or other property right.

          B.   Associates shall indemnify, defend and hold harmless WORLDSPAN,
               its directors, affiliates, partners officers, employees and
               agents from and against all liabilities, suits, costs, damages
               and claims (including but not limited to litigation costs,
               expenses and reasonable attorneys' fees) which may be suffered
               by, accrued against, charged to or recoverable from WORLDSPAN,
               its directors, affiliates, partners, officers, employees or
               agents by reason of or in connection with Associate's performance
               or failure to perform, or improper performance of any of
               Associate's obligations under this Agreement.

     9.   DISCLAIMER
          ----------

          A.   WORLDSPAN DISCLAIMS AND ASSOCIATE HEREBY WAIVES ALL WARRANTIES,
               EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO, ANY WARRANTY
               OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR
               INTENDED USE, OR ANY LIBILITY IN NEGLIGENCE, TORT, STRICT
               LIABILITY OR OTHERWISE, WITH RESPECT TO THE WORLDSPAN SYSTEM OR
               FOR EQUIPMENT, DATA OR SERVICES FURNISHED HEREUNDER.  ASSOCIATE
               AGREES THAT WORLDSPAN SHALL NOT BE LIABLE FOR ANY INDIRECT,
               INCIDENTIAL, CONSEQUENTIAL OR PUNITIVE DAMAGES UNDER ANY
               CIRCUMSTANCES, INCLUDING, BUT NOT LIMITED TO, LOSS OF REVENUES,
               EVEN IF ADVISED OF THE RISK OF SUCH DAMAGES IN ADVANCE.

          B.   WORLDSPAN shall have no responsibility or liability to Associate
               due to the failure of any WORLDSPAN User or customer of any such
               WORLDSPAN User to remit to Associate for sales made or any other
               dispute relating to the arrangement between Associate and such
               WORLDSPAN User or any such customer of such WORLDSPAN User.

                                       6
<PAGE>

          C.   WORLDSPAN shall not be liable to Associate, nor deemed to be in
               default of this Agreement, on account of any delays, errors,
               malfunctions or breakdowns with respect to the WORLDSPAN System,
               equipment, data or services provided hereunder, unless such
               delay, error, malfunction or breakdown results solely from the
               gross negligence or willfull misconduct of WORLDSPAN.

     10.  CONFIDENTIAL INFORMATION
          ------------------------

          A.   Confidential information disclosed by one party to another,
               including but not limited to the list of WORLDSPAN Users provided
               Associate, are for the exclusive use of the receiving party and
               shall not be disclosed or made available to any other person,
               firm, corporation, or governmental entity in any form or manner
               whatsoever, provided, however, that in the event information,
               materials, or documentation covered by this Agreement is
               subpoenaed or otherwise requested or demanded by any court or
               governmental authority, the receiving party shall give prompt
               notice to the disclosing party prior to furnishing same, and
               shall exercise its best efforts, in cooperation with the
               disclosing party, to quash or limit such request, demand and/or
               subpoena.  The covenants set forth in this Section shall survive
               indefinitely the termination, suspension or cancellation of this
               Agreement.

          B.   WORLDSPAN in no way warrants or represents the number of
               WORLDSPAN Users or that any WORLDSPAN User shall access GRS or
               purchase any Product.

          C.   Title and full and complete ownership rights to all WORLDSPAN
               owned or developed software associated with or contained in the
               WORLDSPAN System or used by WORLDSPAN in the performance of this
               Agreement shall remain with WORLDSPAN. Associate understands and
               agrees that WORLDSPAN's owned or developed software is
               WORLDSPAN's trade secret, proprietary information, and
               confidential information whether any portion thereof is or may be
               copyrighted or patented.


     11.  SYSTEM OPERATING STANDARDS
          --------------------------

          Associate will use equipment leased from WORLDSPAN, if applicable, and
          the WORLDSPAN System in the manner indicated below:

          A.   Associate will take all precautions necessary to prevent
               unauthorized and improper use and operation of the equipment and
               the WORLDSPAN System.  Misuse of the WORDSPAN System or equipment
               shall include, but is not limited to, speculative booking or
               reservation of space in anticipation of demand, interference with
               WORLDSPAN's operations or systems, or improper access.
               Associate's improper use of the WORLDSPAN System or equipment
               will be considered a material breach of the Agreement, and
               WORLDSPAN will have the right to deny or suspend Associate's
               access to the WORLDSPAN System immediately without notice or
               liability to Associate.

          B.   Associate will not use the WORLDSPAN System, of any data or
               information from the WORLDSPAN System, to develop or publish any
               reservation, rate, or tariff guide. Associate will not publish,
               disclose or otherwise make available to any third party the
               compilations of data from or through the WORLDSPAN System.



                                       7
<PAGE>

12.       TERMINATION
          -----------

          A.   If Associate fails to timely make any payment required pursuant
               to this Agreement and such failure continues for fifteen (15)
               days after written notice by WORLDSPAN, WORLDSPAN may, in its
               sole discretion, suspend services to Associate in whole or in
               part or terminate this Agreement in its entirety.

          B.   Except for Associate's failure to make timely payment, if either
               party shall refuse, neglect or fail to perform, observe or keep
               any of the material covenants, terms or conditions contained
               herein to be performed, observed or kept, and such refusal,
               neglect or failure shall continue for a period of thirty (30)
               days after written notice, the non-defaulting party shall have
               the right, in addition to any other right or remedy it may have,
               to terminate this Agreement.

          C.   If either party petitions for relief under the Bankruptcy Code of
               the United States, or if voluntary bankruptcy proceedings are
               instituted by a party under any federal, state or foreign
               insolvency laws, or if such a proceeding is imminent, or if it is
               adjudged bankrupt, or if it makes any assignment for the benefit
               of its creditors of all of its assets; or if an involuntary
               petition is filed or execution issued against it and not
               dismissed or satisfied within thirty (30) days; or if its
               interest hereunder passes by operation of law to any other
               person, except in case of merger or acquisition the other party
               may, at its option, terminate this Agreement by written notice
               provided, however, that all monies owed hereunder prior to the
               date of termination shall be immediately due and payable.

     13.  NOTICES
          -------

          All notices, requests, demands or other communications hereunder shall
          be in writing, hand delivered, sent by first class mail, overnight
          mail, facsimile or teletype and shall be deemed to have been given
          when received at the following addresses:


     If to WORLDSPAN:

                    WORLDSPAN, L.P.
                    300 Galleria Parkway, NW
                    Atlanta, Georgia 30339
                    U.S.A.
                    Teletype: HDQPM1P
                    Facsimile: 770-583-7296
                    ATTN:  Manager - WORLDSPAN Travel Suppliers


     With a copy to:

                    WORLDSPAN, L.P.
                    300 Galleria Parkway. NW
                    Atlanta, Georgia 30339
                    U.S.A.
                    Teletype: ATLMSIP
                    Facsimile: 770-583-7878
                    ATTN:   Legal Department



                                       8
<PAGE>

            If to Associate:
                            ________________________________
                            ________________________________
                            ________________________________
                            ________________________________
                            Teletype:_________________________
                            Facsimile:_________________________
                            ATTN:___________________________


     Any notice provided by facsimile or teletype which is received after 4:00
     p.m. local time shall be deemed received the following business day.  A
     party may change its addresses for notice on not less than ten (10) days
     prior written notice to the other party.

14.  GENERAL PROVISIONS
     ------------------

     A.   Nothing in this Agreement is intended or shall be construed to create
          or establish an agency, partnership, or joint venture relationship
          between the parties hereto.

     B.   Neither party shall make any use of the other party's company name,
          logo, trademarks or service marks, except following the party's prior
          written consent, except that nothing contained in this provision shall
          be construed as preventing either party from publicizing the existence
          and general nature of this Agreement.

     C.   The captions appearing in this Agreement have been inserted as a
          matter of convenience and in no way define, limit, or enlarge the
          scope of this Agreement or any of the provisions thereof.

     D.   No waiver by either party of any one breach of this Agreement shall
          constitute a waiver of any other breach of the same or any other
          provision hereof and no waiver shall be effective unless made in
          writing.  The right of either party to require strict performance and
          observance of any obligations hereunder shall not be affected in any
          way by any previous wavier, forbearance of course of dealing.

     E.   Except for Associate's obligation to make payments hereunder, neither
          party will be deemed in default of this Agreement as a result of a
          failure to perform its obligations caused by acts of God or
          governmental authority, strikes or labor disputes, fire, acts of war,
          failure of third party suppliers, or for any other cause beyond the
          control of the party.

     F.   Associate shall not sell, assign, license, sub-license or otherwise
          convey in whole or in part to any third party this Agreement or the
          services provided hereunder without the prior written consent of
          WORLDSPAN, which consent shall not be unreasonably withheld.

     G.   This is a non-exclusive agreement. Similar agreements may be entered
          into by either party with any other person.

     H.   This Agreement shall be governed by, construed and enforced according
          to the laws of the State of Georgia and of the United States of
          America, without regard to its conflict of laws and rules. Each party
          hereby consents to the non-exclusive jurisdiction of the courts of the
          State of Georgia and United States Federal Courts located in Georgia
          to resolve any dispute arising out of this Agreement.



                                       9
<PAGE>

     I.   This Agreement embodies the entire understanding of the parties and
          supersedes all other prior agreements and understandings related to
          the subject matter hereof, including but not limited to any prior
          "WORLDSPAN Global Reference System Agreement." This Agreement may be
          modified only by a further written agreement signed by the parties
          hereto.

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed by their duty authorized undersigned representatives of the day and
year first above written.

ASSOCIATE:                                WORLDSPAN, L.P.

Orbit Network Inc.
--------------------------
(Company Name)

By: /s/ Pat Tidmore                      /s/ Lori Schwarofer
    ----------------------               --------------------------
(Signature)                              Market Development Manager
                                         WORLDSPAN Travel Suppliers
C. Patton Tidmore
--------------------------
(Print/Type Name)

Vice President, Marketing
--------------------------
(Print/Type Title)

                                       10
<PAGE>

                                   WORLDSPAN

                        EQUIPMENT AND SOFTWARE ADDENDUM


     THIS WORLDSPAN Equipment and Software Addendum ("Addendum") is effective
this 2nd day of August, 1999, between WORLDSPAN, L.P., having its principal
place of business at 300 Galleria Parkway, N.W., Suite 2100, Atlanta, Georgia
30339 ("WORLDSPAN"), and Orbit Network Inc. ("Associate"), having its principal
place of business at 505A San Marin Drive, Suite 300, Novato, CA  94945.

     WHEREAS, WORLDSPAN desires to lease certain computer hardware, terminals,
partners and other devices ("Equipment"), to license certain software
("Software"), and to provide certain services, and Associate desires to accept
and pay for same, all according to the terms of this Addendum.

     NOW, THEREFORE, it is agreed:

SECTION 1.  PROVISION OF EQUIPMENT, SOFTWARE AND SERVICES
---------------------------------------------------------

A.   WORLDSPAN agrees to lease to Associate, and Associate agrees to lease from
     WORLDSPAN, Equipment, Software and services according to the terms of this
     Addendum. Any Equipment and Software provided by WORLDSPAN will be used by
     Associate solely for the purposes and functions necessary for Associate to
     provide services to authorized users of the WORLDSPAN System and in strict
     accordance with training and operating procedures, instructions, and rules
     established by WORLDSPAN from time to time. Associate agrees to pay
     WORLDSPAN for the Equipment, Software, services, communication charges and
     other charges as set forth herein. Title to and ownership of the Equipment
     and Software shall at all times remain in WORLDSPAN.

B.   Associate agrees that it will not modify any of the Equipment used to
     access the WORLDSPAN System, substitute different Equipment, or remove,
     relocate or move the Equipment, without the prior written consent of
     WORLDSPAN.  At the termination of the Agreement, Associate agrees to
     immediately return to WORLDSPAN, shipping prepaid, all of the Equipment
     provided by WORLDSPAN in the same condition as delivered to Associate,
     normal wear and tear excepted.

SECTION 2.  INSTALLATION, RELOCATION AND REMOVAL
------------------------------------------------

A.   WORLDSPAN shall confer with Associate to determine where Associate would
     prefer to locate the Equipment on Associate's premises. Associate shall be
     responsible, at its expense, for preparing the area for the installation of
     the Equipment. This preparation will include items such as installing
     cables and data communication lines, arranging for electrical service and
     locating the Equipment in the area of installation. The area must be
     prepared in accordance with the specifications provided by the
     manufacturers of the Equipment and also by the suppliers of electrical and
     communication lines. Associate must also insure that the installation does
     not violate any building or electrical codes or any other law, ordinance or
     regulation.

B.   WORLDSPAN will notify Associate of the proposed date of installation, and
     WORLDSPAN will use reasonable business efforts to complete installation
     within thirty (30) days of such proposed date. WORLDSPAN shall not be
     responsible for any delay in installation caused by Associate's failure to
     prepare the installation area.

C.   Associate agrees that only WORLDSPAN and its service representatives are
     permitted to install, relocate, remove, or move the Equipment. Associate
     shall give WORLDSPAN at least sixty (60) days prior written notice of
     Associate's desire to relocate, remove or move the Equipment, and
<PAGE>

SECTION 3.  REPAIRS AND MAINTENANCE
-----------------------------------

A.   WORLDSPAN (or its service representative) will provide, at its own expense,
     normal repairs and maintenance for the Equipment. These services shall be
     provided from 8:00 a.m. to 5:00 p.m. local time, Monday through Friday,
     holidays excepted. Except in those instances that WORLDSPAN has
     specifically instructed Associate on repair and maintenance procedures,
     Associate will not attempt to perform repairs or maintenance on the
     Equipment.

B.   Associate shall maintain a written record of each occasion that repairs or
     maintenance are performed. Associate agrees that it will make those records
     available to WORLDSPAN for inspection upon request.

C.   Except for damage caused by WORLDSPAN or its service representative,
     Associate shall pay WORLDSPAN for repair and maintenance services when
     damage results from: (1) accident, negligence or misuse; (2) failure or
     variation of electrical power; (3) failure to properly maintain the
     installation site, heating, air conditioning or humidity control; (4)
     causes other than ordinary use; or (5) attachment or modification to the
     WORLDSPAN Equipment performed or provided by anyone other than WORLDSPAN or
     its service representative.

SECTION 4.  USE OF EQUIPMENT AND SYSTEM
---------------------------------------

A.   Associate agrees that it will operate the Equipment and access the
     WORLDSPAN System in compliance with all operating and other instructions.
     Associate shall prevent unauthorized operation and use of the Equipment and
     the WORLDSPAN System. Misuse of the Equipment, including without
     limitation, speculative booking or reservation of space in anticipation of
     demand, interference with WORLDSPAN's operations or systems, or improper
     access will be a material breach by Associate of the Agreement and this
     Addendum, and WORLDSPAN will have the right to deny or suspend Associate's
     access to the WORLDSPAN System immediately without notice or liability to
     Associate.

B.   Associate will protect the Equipment, Software, training materials and
     Confidential Information from loss, theft, and damage and will return them
     to WORLDSPAN at the termination of the Agreement in good condition and
     repair. Associate is responsible for any loss, damage, or theft of any item
     provided by WORLDSPAN.

SECTION 5. SOFTWARE AND CONFIDENTIAL INFORMATION
------------------------------------------------

A.   For the purposes of this Section 5, Confidential Information shall include
     WORLDSPAN's proprietary information, data, drawings, specifications,
     documentation, manuals, plans and software, except: (1) information known
     to Associate prior to disclosure by WORLDSPAN; (2) information developed by
     Associate independent of any confidential materials provided by WORLDSPAN;
     or (3) information which is publicly known or publicly available in the
     relevant trade or industry. Confidential Information supplied by WORLDSPAN
     to Associate pursuant to this Addendum is for the exclusive use of
     Associate and shall not be disclosed or made available to any other person,
     firm, corporation or governmental entity in any form or manner whatsoever;
     provided, however, that in the event Confidential Information is subpoenaed
     or otherwise requested or demanded by any court or governmental authority,
     Associate shall give written notice to WORLDSPAN prior to furnishing the
     same and shall exercise its best efforts, in cooperation with WORLDSPAN, to
     quash or limit such request, demand and/or subpoena. Associate's
     obligations include treating Confidential Information with at least the
     concern and protective measures accorded any trade secrets and confidential
     materials of Associate. Nothing herein shall be construed to require the
     disclosure of Confidential Information to Associate, or to require
     Associate to accept Confidential Information.


                                      -2-
<PAGE>

B.   As between WORLDSPAN and Associate, title and full and complete ownership
     rights to all Software and Confidential Information utilized by WORLDSPAN
     or provided to Associate in the performance of this Addendum shall remain
     with WORLDSPAN. Associate agrees that WORLDSPAN owned, licensed or
     developed Software is WORLDSPAN's or a third party's trade secret and
     proprietary information, regardless of whether any portion thereof is or
     may be validly copyrighted or patented. Any Software provided to Associate
     is provided by license only. Associate's license is non-exclusive, non-
     transferable and is limited to the right to use such Software in the United
     States during the term of this Addendum only according to guidelines
     established by WORLDSPAN from time to time. Such Software shall be utilized
     by Associate only in accordance with this Addendum, and shall not be
     copied, duplicated, reproduced, manufactured or disclosed in any form or by
     any media to any other person or party. Associate agrees to abide by any
     terms imposed by any third party that has directly or indirectly licensed
     Associate to use Software pursuant to this Addendum. Upon termination of
     this Addendum, Associate shall immediately return to WORLDSPAN any Software
     provided by WORLDSPAN. Associate's license to use the Software shall
     terminate upon termination of the Agreement. Nothing herein shall be
     construed to require WORLDSPAN to deliver any Software to Associate, or to
     require Associate to accept such Software.

SECTION 6. TRAINING
-------------------

A.   WORLDSPAN agrees to provide initial training at no additional charge, to a
     mutually agreed upon number of Associate's employees at WORLDSPAN's
     training facilities. WORLDSPAN shall provide transportation between the
     airport and the training facility and Associate shall bear the cost of
     other ground transportation and meals for its employees during training.
     WORLDSPAN will make lodging arrangements, at Associate's expense, and, when
     possible, provide complimentary air transportation for Associate's
     employees to and from initial training. Associate shall pay WORLDSPAN for
     the cost of any additional or recurrent training at WORLDSPAN's then
     existing rates for such training. All training classes are taught in the
     English language.

B.   WORLDSPAN may, upon reasonable notice to Associate, during normal business
     hours of Associate, monitor and evaluate the proficiency of Associate's
     employees' use of the WORLDSPAN System. WORLDSPAN shall use reasonable
     efforts to ensure that this monitoring and evaluation shall be conducted in
     a manner that will not unreasonably interfere with Associate's business. If
     WORLDSPAN determines that Associate's employees are not properly using the
     Equipment or the WORLDSPAN System, Associate and WORLDSPAN will arrange for
     Associate's employees to receive additional training sufficient to assure
     proficient and effective use. Associate shall bear all expenses associated
     with such additional training.

SECTION 7. ADDITIONAL CHARGES
-----------------------------

A.   Associate shall promptly pay or reimburse WORLDSPAN, as appropriate, for
     all sales, use, personal property, license and franchise taxes, duties,
     import fees or other charges or assessments charged or levied in connection
     with the delivery, installation, maintenance, possession, use or removal of
     the Equipment or WORLDSPAN System, as well as any other governmental
     charges or assessments which arise as a result of this Addendum or which
     may be imposed (excluding any taxes on or measured by the net income of
     WORLDSPAN).

B.   Associate agrees to pay WORLDSPAN for maintenance or repair services not
     provided by WORLDSPAN according to Section 3 of this Addendum, or for
     services provided outside of the established work periods, if requested by
     Associate.

C.   Associate shall reimburse WORLDSPAN for any costs incurred by WORLDSPAN to
     collect amounts due under the Addendum including, but not limited to,
     reasonable attorneys' fees and court costs.

                                      -3-
<PAGE>

SECTION 8.  ADDITIONAL FUNCTIONS
--------------------------------

     Additional and replacement functions, services or equipment may be offered
by WORLDSPAN from time to time.  Any additional and replacement functions,
services, software or equipment will be provided to Associate, as available,
subject to WORLDSPAN's then prevailing terms and charges.

SECTION 9.  INDEMNIFICATION AND INSURANCE
-----------------------------------------

A.   Associate shall indemnify, defend and hold harmless WORLDSPAN, its
     partners, affiliates, officers, directors, employees and agents from and
     against any and all liabilities, suits, costs, damages and claims
     (including litigation costs, expenses and reasonable attorneys' fees) which
     may be suffered by, accrued against, charged to or recoverable from
     WORLDSPAN, its partners, affiliates, officers, directors, employees or
     agents by reason of or in connection with Associate's performance or
     failure to perform, or improper performance of, any of Associate's
     obligations under this Addendum.

B.   Associate shall take all necessary precautions to protect the WORLDSPAN
     System and the Equipment, Software and training materials. At its own cost,
     Associate shall procure and maintain insurance in an amount not less than
     the Minimum Insurance Value provided in Schedule A, insuring the Equipment
     and Software against all risk of loss, or damage including, without
     limitation, the risks of fire, theft and other such risks as are
     customarily insured in a standard all risk policy. Associate acknowledges
     that the Minimum Insurance Value amount includes only equipment and
     software replacement charges and that Associate may also be obligated to
     pay WORLDSPAN for installation, removal or other services rendered in
     connection with the replacement of lost or damaged Equipment or Software.
     Such insurance shall also provide the following:

     1.   Full replacement value coverage for the Equipment and Software;

     2.   An endorsement naming WORLDSPAN as co-insured and as a loss payee with
          regard to the Equipment and other items provided by WORLDSPAN
          hereunder; and

     3.   An endorsement requiring the insurer to give WORLDSPAN at least thirty
          (30) days prior written notice of any intended cancellation; non-
          renewal, or material change in coverage.

          Failure of Associate to maintain the insurance coverage required
     herein shall not relieve Associate of its responsibility to return the
     Equipment or Software to WORLDSPAN, or to pay WORLDSPAN the full
     replacement value of any Equipment or Software which is damaged or
     destroyed. Upon request, Associate shall provide WORLDSPAN a certificate or
     certificates of insurance reflecting the insurance coverage required by
     this Section.

SECTION 10.  LIMITATION OF LIABILITY
------------------------------------

A.   WORLDSPAN DISCLAIMS, AND ASSOCIATE HEREBY WAIVES, ALL WARRANTIES, EXPRESS
     OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE OR INTENDED USE, OR
     ANY LIABILITY IN NEGLIGENCE, TORT, STRICT LIABILITY OR OTHERWISE.  WITH
     REGARD TO ANY CRS, EQUIPMENT, SOFTWARE OR DATA PROVIDED HEREUNDER,
     ASSOCIATE AGREES THAT WORLDSPAN SHALL NOT BE LIABLE UNDER ANY CIRCUMSTANCES
     FOR ANY INDIRECT, CONSEQUENTIAL, SPECIAL OR PUNITIVE DAMAGES, INCLUDING,
     BUT NOT LIMITED TO, LOSS OF REVENUES, EVEN IF ADVISED OF THE RISK OF SUCH
     DAMAGES IN ADVANCE.


                                      -4-
<PAGE>

B.   WORLDSPAN shall not be liable to Associate, nor deemed to be in default of
     this Addendum, on account of any delays, errors, malfunctions or breakdowns
     with respect to the WORLDSPAN System, Equipment, data or services provided
     hereunder, unless such delay, error, malfunction or breakdown results
     solely from the gross negligence or willful misconduct of WORLDSPAN.

SECTION 11.  PAYMENT
--------------------

A.   Associate agrees to pay WORLDSPAN all amounts due pursuant to this
     Addendum, including but not limited to the charges set forth on Schedule A,
     within thirty (30) days of invoice.

B.   All charges pursuant to this Addendum are subject to change upon thirty
     (30) days' prior written notice to Associate by WORLDSPAN.

SECTION 12.  NOTICES
--------------------

     All notices, requests, demands or other communications hereunder shall be
in writing, hand delivered, sent by first class mail, overnight mail, facsimile
or teletype and shall be deemed to have been given when received at the
following addresses:

     If to WORLDSPAN:

          WORLDSPAN, L.P.
          300 Galleria Parkway, NW
          Atlanta, Georgia  30339
          U.S.A.
          Teletype:  HDQAS1P
          Facsimile:  770/583-7296
          ATTN:  Manager WORLDSPAN Travel Suppliers

     with a copy to:

          WORLDSPAN, L.P.
          300 Galleria Parkway, NW
          Atlanta, Georgia  30339
          U.S.A.
          Teletype:  ATLMS1P
          Facsimile:  770-583-7878
          ATTN:  Legal Department

     if to Associate:

          -----------------------------

          -----------------------------

          -----------------------------

          -----------------------------

          -----------------------------
          Teletype:
                   --------------------
          Facsimile:
                   --------------------
          ATTN:
               ------------------------

SECTION 13.  TERM AND TERMINATION
---------------------------------

A.   This Addendum shall become effective on the date first written above, and
     shall continue in full force and effect for an initial term of one year,
     and thereafter until terminated by either party upon not less than thirty
     (30) days prior written notice to the other party, unless earlier
     terminated

                                      -5-
<PAGE>

     as provided herein.  This Addendum may be terminated without automatically
     terminating the Agreement.

B.   If any of the following events of default occur, then WORLDSPAN shall give
     Associate notice that such an event has occurred and if Associate falls
     fully to cure such default within fifteen (15) days of such notice, then
     WORLDSPAN may, following such failure to cure, terminate the Addendum, or
     suspend services under the Addendum in whole or in part:

     1.   Associate ceases to do business as a going concern, files a voluntary
          petition in bankruptcy, makes an assignment for the benefit of
          creditors of all or substantially all of its assets, or petitions for
          reorganization, liquidation or dissolution under any federal or state
          bankruptcy law or similar law; or

     2.   Associate uses the Equipment, the Software or the CRS for any improper
          purpose; or

     3.   Associate is in default of any material obligation owed WORLDSPAN
          pursuant to this Addendum; or

     4.   Associate fails to timely make any payment required pursuant to this
          Addendum; or

     5.   Associate terminates or cancels this Addendum or any part thereof.

C.   If any of the following events of default occur, Associate shall give
     WORLDSPAN notice that such an event has occurred and if WORLDSPAN fails to
     cure such default within fifteen (15) days of such notice, then Associate
     may, following such failure to cure, terminate this Addendum:

     1.   WORLDSPAN ceases to do business as a going concern, files a voluntary
          petition in bankruptcy, makes an assignment for the benefit of
          creditors of all or substantially all of its assets, or petitions for
          reorganization, liquidation or dissolution under any federal or state
          bankruptcy law or similar law; or

     2.   WORLDSPAN provides any Equipment pursuant to this Addendum that fails
          in its essential purpose and such failure prevents Associate from
          reasonably conducting its business, which Equipment is not replaced or
          repaired by WORLDSPAN; or

     3.   WORLDSPAN is in default of any material obligation owed Associate
          pursuant to this Addendum.

D.   Upon termination of this Addendum pursuant to this Section 13, WORLDSPAN
     shall be entitled immediately to retake possession of the Equipment and
     Software without any process of law and terminate access to the CRS.
     Termination of the Addendum for any reason shall not relieve either party
     of rights or obligations arising prior to the effective date of
     termination. Nothing in this Section 13 shall be construed as a limitation
     upon any rights or remedies the parties may have elsewhere in this
     Addendum, at law, equity, or otherwise.

SECTION 14.  GENERAL PROVISIONS
-------------------------------

A.   Nothing in this Addendum is intended to or shall be construed to create or
     establish an agency, partnership, or joint venture relationship between the
     parties hereto.

B.   Associate shall not make any use of any WORLDSPAN name, logo, trademark or
     service mark without WORLDSPAN's prior written consent.


                                      -6-
<PAGE>

C.   Headings used in this Addendum have been inserted as a matter of
     convenience only and in no way define, limit or enlarge the scope of this
     Addendum or any of its provisions. Capitalized terms shall have the
     meanings assigned in the Agreement.

D.   In the event that any material provision of this Addendum is determined to
     be invalid, unenforceable or illegal, then such provision shall be deemed
     to be superseded and the Addendum modified with a provision which most
     nearly corresponds to the intent of the parties and is valid, enforceable
     and legal.

E.   This Addendum shall be governed by, construed and enforced according to the
     laws of the State of Georgia and of the United States of America, without
     regard to its conflict of laws and rules. Each party hereby consents to the
     non-exclusive jurisdiction of the courts of the State of Georgia and United
     States Federal Courts located in Georgia to resolve any dispute arising out
     of this Addendum.

F.   Except for Associate's obligation to make payments hereunder, neither party
     will be deemed in default of this Addendum as a result of a failure to
     perform its obligations caused by acts of God or governmental authority,
     strikes or labor disputes, fires, acts of war, failure of third party
     suppliers, or for any other cause beyond the control of the party.

G.   No waiver of any breach of any provision of this Addendum by either party
     shall constitute a waiver of any subsequent breach of the same or any other
     provisions thereof, and no waiver shall be effective unless made in
     writing.

H.   This Addendum constitutes the final and complete understanding between the
     parties concerning the subject matter hereof. Any prior agreements,
     understandings or communications written or otherwise are deemed superseded
     by this Addendum. This Addendum may be modified only by a further writing
     executed by the parties hereto.

     IN WITNESS WHEREOF, the parties have caused this Addendum to be executed by
their duly authorized undersigned representatives.


ASSOCIATE:                                   WORLDSPAN, L.P.


Orbit Network Inc.
------------------------------
(Print Company Name)

                                             /s/ Lori Schwarofer
By:/s/ Pat Tidmore                           -------------------
   ---------------                           Market Development Manager
   (Signature)                               WORLDSPAN Travel Suppliers

C. Patton Tidmore
------------------------------               August 2, 1999
(Print Name)                                 --------------------------
                                             Date
Vice President, Marketing
------------------------------
Title

                                      -7-