EXHIBIT 1
  
                          CERTIFICATE OF SELLING SHAREHOLDER
  
  
       The undersigned selling shareholder ("Holder") has requested that
  RENTECH, INC. (the "Company"), include in a Registration Statement on
  Form S-3 certain shares of the Company's common stock (the "Securities")
  desired to be sold by the Holder.  To induce the Company to register such
  Securities for public sale by the Holder:
  
       1.  The Holder represents and warrants to and covenants with the
  Company that:  (i) the Holder has fully and accurately completed the
  Registration Statement Questionnaire for use by the Company in
  preparation of the Registration Statement and the answers and information
  contained therein are true and correct as of the date hereof and will be
  true and correct as of the effective date of the Registration Statement
  and at all times thereafter; (ii) the Holder understands that a current
  prospectus is required to be delivered to any purchaser of the
  Securities; (iii) the Holder has not entered into any agreement, written
  or oral, for the sale of any of the Securities upon terms different from
  those set forth in the Registration Statement; (iv) the Holder is aware
  of and agrees to abide by the provisions of Rule 10b-6 under the
  Securities Exchange Act of 1934 ("1934 Act"), which provides, in essence,
  that the Holder, under certain circumstances, may not bid for or purchase
  any of the Securities covered by the Registration Statement or any
  security of the same class, or any right to purchase any such security,
  and may not attempt to induce any person to purchase any such security or
  right until all Securities covered by such Registration Statement and
  owned by such Holder shall have been sold or withdrawn; and (v) the
  Holder is aware of and agrees to abide by the provisions of Rule 10b-7
  under the 1934 Act which provides that any person who offers to buy or
  buys the common stock of the Company for the purpose of maintaining or
  stabilizing the market price of such common stock to facilitate the sale
  of the Securities may be deemed to have violated rules prohibiting
  manipulation of market prices for securities.
  
       2.  The Holder agrees to promptly give notice to the Company in the
  event any of the information provided by the Holder in the Registration
  Statement Questionnaire or any of the information relating to the
  Securities owned by the Holder included in the Registration Statement, or
  to the plan of distribution as set forth in the Registration Statement
  (copies of which are enclosed), should become materially false or
  misleading.  The Holder acknowledges and agrees that there may
  occasionally be times when the Company must temporarily suspend the use
  of the prospectus and that the Holder will not be able to sell any of the
  Securities during the suspension period.
  
       3.  To the extent permitted by law, the Holder will indemnify and
  hold harmless the Company and its officers, directors and any person who
  controls the Company within the meaning of the Securities Act of 1933, as
  amended, for any claims, damages or liabilities (and actions related
  thereto) arising out of any untrue or alleged untrue statement of any
  material fact or based upon the omission or alleged omission to state a
  material fact required to be stated in the Registration Statement,
  prospectus or amendments or to make statements therein not misleading,
  but only to the extent that such untrue or alleged untrue statement or
  omission or alleged omission was made in reliance upon and in conformity
  with written information furnished by Holder for use in connection with
  such registration. 
  
       Dated this         day of                           , 1997.
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  Signature                           Signature (if held jointly)
  
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  Print or Type Name                  Print or Type Name