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                                                                   EXHIBIT 10.21

[LOGO]
MORRISON KNUDSEN CORPORATION

MORRISON KNUDSEN PLAZA
P.O. BOX 73
BOISE, IDAHO U.S.A. 83729

ALVIA L. HENDERSON
VICE PRESIDENT
HUMAN RESOURCES


April 10, 2000


Mr. Vincent L. Kontny
601 Lido Park Drive, Unit 2AB
Newport Beach, CA 92663


RE: OFFER OF EMPLOYMENT

Dear Vince:

On behalf of Morrison Knudsen Corporation (the "Company"), I am pleased to offer
you employment pursuant to the terms and conditions set forth in this letter and
subject to Board of Director approval.

1)   POSITION AND SERVICES TO BE RENDERED. The Company hereby agrees to employ
     you as Chief Operating Officer. You accept such employment and agree to
     devote your time and attention exclusively to rendering services to the
     Company. The Company agrees to your continuing to serve on the Board of
     Directors of CDI. You will report to the Company's Chief Executive Officer.
     Your actual first date of active employment with the Company will be April
     10, 2000 (the "Effective Date").

2)   SALARY. You will receive an annual salary of $450,000 commencing as April
     10, 2000, payable in accordance with the Company's normal payroll practice
     (i.e., every two weeks). Your position will be a regular full-time
     position. The Company will review your base salary annually to determine
     any increase.

Subject to approval by the Covered Employees Subcommittee ("the Subcommittee")
of the Compensation Committee, and ratification by the Compensation Committee
and by the Board of Directors:

3)   STOCK OPTIONS. You will be granted options to purchase 200,000 shares of
     the Company's common stock, under the Company's Stock Option Plan, at a
     price equal to the per share closing price of the Company's stock, as of
     the date the grant is approved by the Board of Directors. It is anticipated
     that this approval will be granted on or about April 14, 2000.

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                                                               Vincent L. Kontny
                                                                  April 10, 2000
                                                                          Page 2


     The options shall all vest in 12 months, on April 14, 2001. The Board of
     Directors has the authority to change the vesting period. The exercise
     period of these options will be five years from termination of employment.

4)   FRINGE BENEFITS. You will be entitled to all other group plan and other
     benefits that are normally offered to regular full-time salaried employees:

     o    401(k) Savings Plan: The Company will match every dollar you
          contribute to the plan, up to 5% of your eligible compensation
          (maximum eligible compensation is $170,000).

     o    Group medical and dental plan and all other benefits as described in
          the Handbook.

     o    Vacation: The Company's PTO policy provides for three weeks of paid
          time off during each of the first 5 years of service, 4 weeks during
          years 5-19, and 5 weeks after 20 or more years of service.

     o    Deferred Compensation Plan: The Company has a deferred compensation
          plan for certain levels of management; as a senior executive of the
          company you would be eligible to participate. This plan allows for
          deferrals of up to 50% of base salary and up to 100% of bonuses.

5)   CONTINGENCIES. This employment offer must be contingent upon the following:

     a.   Your passing of a drug screen test, pursuant to the Company's
          Substance Abuse Prevention Program, and your continued compliance with
          such program. After reporting to work, you will also be required to
          complete an "Employment Certification" form that complies with the
          passing of the Drug-Free Workplace Act of 1988.

     b.   Your compliance with the following laws:

          o    In accordance with Public Law 99-603, the Immigration and
               Naturalization Act of 1986, this offer is made pending receipt of
               verifiable documentation from you confirming your eligibility for
               employment under the terms and conditions of this Act. Proof of
               U.S. citizenship or adequate identification is required before
               any hire can be processed. You must present acceptable documents
               for employment eligibility verifications when you report for your
               first day of work.

          o    In accordance with Public Law 100-679, the Office of Federal
               Procurement Policy Act Amendments of 1988, the Company is
               prohibited, for a period of two years, from hiring former
               government officials or employees (military or civilian) who
               participated personally and substantially in the conduct of any
               Federal agency procurement. Consequently, this offer is
               contingent upon receipt of information
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                                                               Vincent L. Kontny
                                                                  April 10, 2000
                                                                          Page 3

               from you that your employment with the Company will not result in
               a violation of the Procurement Policy Act. You will be required
               to complete an employee certification form verifying your prior
               employment before your employment with the Company begins.

By accepting this employment offer, you agree to the terms and conditions
established herein. To indicate your acceptance of this offer, please sign the
facsimile copy of this letter and return it to me. An original will be provided
for your signature at a later date. If you have any questions, please do not
hesitate to contact me.


Sincerely,



Alvia L. Henderson
Vice President-Human Resources


Attachment


AGREED AND ACCEPTED:


/s/ Vincent L. Kontny
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Vincent L. Kontny


DATE:

         4/12/00
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