Exhibit 5
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                         CEC Resources Ltd. Letterhead


                               February 2, 2000


     Re:  Exchange Offer for Stock of CEC Resources Ltd.

Dear Shareholder of CEC Resources Ltd.:

     In January 2000 we sent to you materials regarding the exchange offer by
Carbon Energy Corporation for all outstanding shares of CEC Resources Ltd.  The
exchange offer is very important to you and the future of CEC Resources.  The
Board of Directors of CEC has unanimously recommended that you accept the
exchange offer.

     The exchange offer is the final step in combining CEC Resources with
Bonneville Fuels Corporation.  We used the exchange offer, in lieu of other
structures for the combination, such as a merger, in order to avoid adverse
income tax consequences to CEC.  The exchange offer is to provide you as a CEC
shareholder with the opportunity to own shares in Carbon Energy, which will have
both Bonneville Fuels and CEC Resources as its subsidiaries.

     By accepting the exchange offer, you will receive one share of Carbon
Energy stock for each share of CEC Resources.  Carbon Energy is a Colorado
corporation, and we expect that the common stock of Carbon Energy will be listed
on the American Stock Exchange after the exchange offer.  CEC Resources is an
Alberta, Canada corporation, and we anticipate that CEC Resources common stock
will be delisted from the American Stock Exchange after the exchange offer.  It
is possible that CEC Resources will not be traded on any established public
market after the exchange offer.

     The exchange offer expires on February 17, 2000.  Please act now so you can
receive Carbon Energy shares.

     If you need any additional materials, including a letter of transmittal, or
if you have any questions about how to complete the documents, please contact me
or Kevin Struzeski at (303) 860-1575 or contact our exchange agent, Harris
Trust, at (212) 701-7624.

                              Very truly yours,

                              CEC RESOURCES LTD.


                              By:  /s/ Patrick R. McDonald
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                                 Patrick R. McDonald, President