SYNTROLEUM CORPORATION - SYNTROLEUM PLAZA - 1350 SOUTH BOULDER - SUITE 1100 -
                         TULSA, OKLAHOMA, 74119-3295 USA
                      (918) 592-7900  -  FAX (918) 592-7979


                                 AUGUST 3, 2000



Commonwealth  of  Australia
represented  by  the  Department  of  Industry  Science
and  Resources  (Invest  Australia)
Level  6,  20  Allara  Street
CANBERRA  ACT  2601

RE:     SUBLICENSE FROM SYNTROLEUM AUSTRALIA LICENSING CORPORATION (SALC) TO THE
COMMONWEALTH  OF  AUSTRALIA  (COMMONWEALTH)
LOAN  FROM  THE  COMMONWEALTH  TO SYNTROLEUM AUSTRALIA CREDIT COOPERATION (SACC)
DEAR  SIR:
Syntroleum Corporation (SYNTROLEUM) is the parent company of SALC and SACC.  The
Commonwealth  proposes  entering into a Sublicense with SALC, a copy of which is
attached  and  marked  "A"  (SUBLICENSE).  The  Commonwealth  proposes  to  make
available to SACC financial accommodation in accordance with a loan agreement, a
copy  of  which  is  attached  and  marked  "C"  (LOAN  AGREEMENT).
SUBLICENCE
In  consideration  of  the Commonwealth at the request of Syntroleum agreeing to
enter  into  the  Sublicense,  Syntroleum  agrees  with  the  Commonwealth that:
(a)     Syntroleum will comply with its obligations under the licence granted by
Syntroleum  to  SALC  a  copy  of  which  is attached and marked "B", (LICENCE);
(b)     if  the  Licence  is terminated or for any other reason ends, Syntroleum
will  itself  at  the request of the Commonwealth grant the Commonwealth (or any
assignee  of  the  Commonwealth)  directly  :
(i)     a  licence  on  the  same  terms  and  conditions as the Sublicense; and
(ii)     a  site  licence  in  respect  of any Licensed Plant (as defined in the
Sublicence)  (SITE LICENCE) on the same terms and conditions as any then current
Site  Licence;
(c)     if  the  Sublicence  or  any Site Licence is terminated or for any other
reason  ends,  (other  than  as  a  result of default by the Commonwealth or its
assignee),  Syntroleum  will itself at the request of the Commonwealth grant the
Commonwealth  (or  any  assignee  of  the  Commonwealth)  directly:
(i)     a  licence  on  the  same  terms  and  conditions as the Sublicense; and
(ii)     a  Site  Licence  in  respect  of any Licensed Plant (as defined in the
Sublicence)  on  the same terms and conditions as any then current Site Licence,
notwithstanding  anything  to the contrary in the Licence, the Sublicence or any
Site  Licence.
Syntroleum  agrees  that  any assignee of the Sublicence or any Site Licence may
rely on this letter notwithstanding this letter is not addressed to the assignee
and  for that purpose the Commonwealth holds the benefit of this letter on trust
for  any  assignee.
LOAN  AGREEMENT
In consideration of the Commonwealth's entry into the Loan Agreement, Syntroleum
agrees  with  the  Commonwealth  that  Syntroleum will use reasonable commercial
efforts to undertake to assist SALC in meeting those of SALC's obligations under
the  Loan Agreement as are specified in Sections 12.1(q) through (t) of the Loan
Agreement; provided, however, that the Commonwealth acknowledges and agrees that
           --------  -------
the  foregoing  agreement  by  Syntroleum  does not, and shall not be deemed to,
constitute a guarantee (or a similar assurance of the payment) of the borrower's
indebtedness  under  the  Loan  Agreement  and  other  Transaction  Documents.
This  letter  is  the  "side  letter"  for  the  purposes of the Loan Agreement.
Yours  faithfully

                    /s/
         -------------------------
         RANDALL  M.  THOMPSON
         VICE  PRESIDENT  AND
         CHIEF  FINANCIAL  OFFICER