<PAGE>
                                                                    EXHIBIT 10.4

                          CONSULTING SERVICES AGREEMENT



         THIS CONSULTING SERVICES AGREEMENT ("Agreement") is entered into as of
the 1st day of June, 2002, by and between WILLBROS GROUP, INC. ("Willbros"), a
Republic of Panama corporation, and LARRY J. BUMP ("Consultant"), an individual
who resides at Houston, Texas.

                              W I T N E S S E T H:

         WHEREAS, Willbros and its affiliates are engaged in the provision of
construction, engineering and other specialty services to the petroleum and
power industries at various locations throughout the world; and

         WHEREAS, Consultant has significant experience and expertise in the
provision of construction, engineering and other specialty services to the
petroleum and power industries throughout the world; and

         WHEREAS, Willbros and its affiliates wish to obtain certain advice and
assistance from Consultant in connection with their business activities and
Consultant is willing to provide such advice and assistance to Willbros and its
affiliates on the terms specified herein;

         NOW, THEREFORE, for and in consideration of the premises and the mutual
promises and covenants hereinafter set forth, the parties hereto agree as
follows:

1.      SERVICES TO BE PERFORMED. The services to be provided by Consultant
        shall consist of advice and assistance in connection with the business
        activities conducted by Willbros and/or its affiliates ("Services").
        All Services shall be rendered at the request and under the general
        direction of the Board of Directors of Willbros. Subject to Paragraph
        11 below, Willbros will provide Consultant such information about the
        business activities of Willbros and its affiliates as Consultant may
        reasonably require in order to carry out the Services.

2.      STANDARD OF PERFORMANCE. All Services will be performed by Consultant
        with a level of skill and care generally exercised by other
        professional consultants engaged in performing the same or similar
        services. In performing the Services, Consultant will comply fully with
        all applicable laws.

3.      RELATIONSHIP. The relationship between Willbros and Consultant shall be
        that of independent contractors and Consultant shall not be or be deemed
        to be a partner, agent or employee of Willbros or any of its affiliates.
        Consultant shall not be eligible to participate in any employee pension,
        insurance, medical, retirement or other fringe benefit plan of Willbros
        or any of its affiliates on account of the provision of Services
        pursuant to this Agreement. It is recognized, however, that Consultant
        is, and expects to continue to be, a Class III member and Chairman


<PAGE>


        of the Willbros Board of Directors as well as a member of various
        committees thereof. Nothing herein shall affect or preclude Consultant's
        eligibility to participate in benefits or other programs offered or
        available to other non-employee members of the Willbros Board of
        Directors.

4.      TERM. This Agreement shall become effective on June 1, 2002 and shall
        continue until (a) December 31, 2004 or (b) the date Consultant ceases
        to serve as Chairman of the Board of Directors of Willbros, whichever
        last occurs.

5.      AVAILABILITY. Upon reasonable advance notice, Consultant shall be
        available to perform Services for a cumulative period of up to ten (10)
        hours per month. Time spent by Consultant in respect of Willbros Board
        of Director meetings, Willbros Board of Director Committee meetings and
        preparation for such meetings shall be deemed to be time expended in
        the performance of Services for purposes of this Paragraph 5.

6.      COMPENSATION. Willbros shall pay Consultant a fee of Ten Thousand U.S.
        Dollars (U.S.$10,000) per month while this Agreement remains in force.
        Such fee shall be payable monthly in arrears.

7.      EXPENSES AND FACILITIES. Willbros shall reimburse Consultant for all
        reasonable business expenses paid or incurred by Consultant directly in
        connection with the performance of the Services, including all costs
        for Consultant and Consultant's spouse to annually attend the
        International Pipe Line and Offshore Contractors Association
        convention. In addition, while this Agreement remains in effect,
        Willbros shall cause its subsidiary, Willbros USA, Inc., to make
        available to Consultant without charge appropriate office space, office
        equipment, secretarial assistance, parking, communications equipment
        and storage space at the Willbros USA, Inc. offices in Houston, Texas.

8.      TAXES. Consultant will pay, be fully responsible for and indemnify
        Willbros and its affiliates against all taxes attributable to the
        compensation payable to Consultant hereunder, including, without
        limitation, income, unemployment, social security and medicare taxes.

9.      INSURANCE. While this Agreement remains in effect, Consultant will
        maintain in force or cause to be maintained in force with respect to any
        automobile operated by Consultant automobile liability insurance with
        limits of not less than One Hundred Thousand U.S. Dollars (U.S.
        $100,000) for any one person for bodily injury or death, Three Hundred
        Thousand U.S. Dollars (U.S. $300,000) for any one accident for bodily
        injury or death and Fifty Thousand U.S. Dollars (U.S. $50,000) for
        property damage. Consultant will provide Willbros evidence of such
        insurance upon its request. While performing consulting services under
        this Agreement, Consultant will be an insured person under such
        accidental death and dismemberment and crisis management insurance
        policies as Willbros maintains in force with respect to certain of its
        employees and consultants who


                                       2
<PAGE>


        are engaged in international business travel. However, Willbros reserves
        the right to modify or terminate such insurance policies at any time.

10.     INDEMNIFICATION. Willbros will indemnify Consultant against any
        liability which arises as a result Consultant's provision of the
        Services, provided such liability is not attributable to Consultant's
        negligence, willful misconduct or failure to comply with the provisions
        of this Agreement.

11.     CONFIDENTIALITY. Except with Willbros' prior written consent or as
        otherwise required by law, Consultant will hold in confidence, not
        disclose to any other person or entity or use for Consultant's own
        personal benefit or the benefit of any other person or entity all
        information regarding Willbros, its affiliates, their respective
        employees, and the business activities conducted by Willbros or its
        affiliates which Consultant obtains or becomes aware of during the
        course of providing the Services, unless such information has become
        publicly available other than as a result of a breach of this Agreement
        by Consultant. The requirements of this Paragraph 11 shall survive
        expiration or termination of this Agreement for a period of two (2)
        years.

12.     NON-COMPETE. While this Agreement remains in force, Consultant will not
        compete with Willbros or its affiliates, or provide advice or assistance
        to any enterprise or entity which is engaged or intends to engage in
        competition with Willbros or its affiliates.

13.     SOLICITATION OF EMPLOYEES. During the term of this Agreement, Consultant
        will not seek to employ or assist any other enterprise or entity with an
        effort to employ any employee of Willbros or its affiliates.

14.     TERMINATION. Either party may terminate this Agreement for cause with
        immediate effect if the other of them fails to comply with its
        obligations under this Agreement and does not cure such failure within
        ten (10) days after notice of such failure has been provided.

15.     NOTICES. Any notice required or permitted to be given under this
        Agreement shall be in writing and shall be effective upon delivery to
        the party at the party's address or facsimile number stated herein.
        Either party may change such party's address stated herein by giving
        notice of the change in accordance with this Paragraph 15.

        If to Willbros:                    Willbros Group, Inc.
                                           c/o Willbros USA, Inc.
                                           Suite 1000
                                           4400 Post Oak Parkway
                                           Houston, Texas
                                           Facsimile:    (713) 403-
                                           Attention:    President


                                       3
<PAGE>


        If to Consultant:                  Larry J. Bump
                                           21 North Wynden, #5
                                           Houston, Texas  77056
                                           Facsimile:  (713)  840-8481

16.     ASSIGNMENT. All rights and obligations herein contained shall inure to
        the benefit of and be binding upon Willbros, Consultant, their
        successors and their permitted assigns. Consultant shall not assign any
        rights or obligations under this Agreement without the prior written
        consent of Willbros.

17.     GOVERNING LAW. This Agreement shall be governed and construed in
        accordance with the laws of the State of Texas, United States of
        America, excluding any conflict of law or other provision referencing
        the laws of another jurisdiction.

18.     ENTIRE AGREEMENT AND WAIVER. This Agreement constitutes the entire
        agreement between the parties hereto with respect to the subject matter
        hereof and supersedes any other understanding entered into by or on
        account of the parties with respect to the subject matter hereof to the
        extent inconsistent herewith. This Agreement may not be changed,
        modified or amended except in writing signed by the parties hereto. The
        failure of either party to exercise any rights under this Agreement for
        a breach thereof shall not be deemed to be a waiver of such rights or a
        waiver of any subsequent breach.

        IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the day and year first above written.


CONSULTANT                            WILLBROS

                                      Willbros Group, Inc.

   /s/  Larry J. Bump                 By:        /s/  Michael F. Curran
---------------------------------         ------------------------------------
          Larry J. Bump                             Michael F. Curran
                                          President and Chief Executive Officer



                                       4