<PAGE>
                                                                  EXHIBIT 10(31)

THIS AGREEMENT is made on 14 October 2002 between:-

(1)      CANARGO LIMITED, a company incorporated and carrying on its activities
         under the laws of Guernsey, having its registered offices at PO Box
         291, Commerce House Les Banques, St. Peters Port, Guernsey (hereinafter
         "CANARGO"); and

(2)      WESTRADE ALLIANCE LLC a Limited Liability Company incorporated under
         the laws of the State of Oregon and having its registered office at
         8497 N.E Fremont Street #229, Portland Oregon 97220 (hereinafter the
         "PURCHASER"), as legally represented by Mr Samson Pkhakadze pursuant to
         a power of attorney granted by the Purchaser dated October 1-st, 2002.

WHEREAS:

(A)      CanArgo is the beneficial and registered owner of the entire issued
         share capital (the "SALE SHARES") of CanArgo Petroleum Products
         Limited, details of which are set out in Schedule 1 to this Agreement
         (the "COMPANY"); and

(B)      CanArgo is willing to sell and the Purchaser is willing to purchase the
         Sale Shares for the consideration and upon the terms and conditions set
         out in this Agreement.

IT IS AGREED:-

1        STRUCTURE

         Subject to the terms of this Agreement CanArgo shall sell, and the
         Purchaser shall purchase, the Sale Shares.

2        PRICE

2.1      The consideration (the "CONSIDERATION") payable by the Purchaser to
         CanArgo for the Sale Shares is US$4,000,000 payable on the dates and in
         the amounts set out below (the "PAYMENT SCHEDULE"):-

<TABLE>
<CAPTION>
      AMOUNT                                           TIME FOR PAYMENT
      ------                                           ----------------
<S>                                                    <C>
      US$500,000 (the "FIRST PAYMENT")                 1 month following the date of this Agreement

      US$500,000 (the "SECOND PAYMENT")                14 January 2003

      US$3,000,000 (the "FINAL PAYMENT")               14 August 2003
</TABLE>

2.2      Any of the First, Second or Final Payments will be deemed to be made on
         the date ("PAYMENT DATE") when the respective Payment has been credited
         to CanArgo's bank account indicated in the Article 3.1 below.

2.3      In the event that payment of the Consideration is not made in
         accordance with the Payment Schedule interest shall accrue daily at the
         rate of 16% per annum on any part of the Consideration which is not
         paid in accordance with the Payment Schedule.

2.4      In the event that either the First Payment or the Second Payment are
         not made on the due date or if the Final Payment is not made on or
         before 30 September 2003 CanArgo shall be entitled to terminate this
         Agreement forthwith and any of the Consideration which has been paid by
         the Purchaser shall not be repaid to the Purchaser but shall be
         retained by CanArgo by way of a non-refundable deposit. In the event of
         termination by CanArgo in the
<PAGE>
         circumstances envisaged by Clause 2.4, the Purchaser shall have no
         claim whatsoever against CanArgo.

         The Payment Schedule shall only be amended in writing by the parties
         hereto. Where any payment falls due on a date which is not a business
         day, the payment shall be due on the immediately preceding business
         day.

3        SECURITY AND CONDUCT OF THE COMPANY PENDING PAYMENT OF THE
         CONSIDERATION

3.1      The Purchaser will become the legal and beneficial owner of the Sale
         Shares only following payment in full of the Consideration and any
         interest due thereon by the Purchaser and receipt of cleared funds by
         CanArgo in the undernoted account:-

         Bank:           HSBC Bank International Limited

         Account:        011-572443-360


         Name:           CanArgo Limited USD Account

         Instructions for transferring funds are as follows:

         Correspondent Bank:
         Bankers Trust Company
         1 Bankers Trust Plaza
         Liberty Street
         New York NY 10006
         A/C No: 04082437
         SWIFT: BKTRUS33

         For further credit of:
         CanArgo Limited USD Account
         Account Number: 011-572443-360
         HSBC Bank International Limited
         PO Box 315
         St Peter Port
         Guernsey GY1 3JQ
         Channel Islands
         SWIFT: MIDLJESH

         Payment will be made by way of Bank Transfers and will not be subject
         to any withholding tax or any other deductions.

3.2      CanArgo confirms that as at the date hereof it controls the business
         and affairs of the Company and that it will continue to do so until the
         Final Payment is made by the Purchaser. CanArgo confirms that to the
         extent possible, it shall continue to run the business and affairs of
         the Company in the ordinary course. CanArgo and the Purchaser confirm
         that until Completion CSOP will continue to be run in the ordinary
         course.

3.3      CanArgo and the Purchaser agree that all dividends declared from the
         date hereof until Completion will be for the Purchaser's benefit
         subject to Completion taking place.

4        WARRANTIES

4.1      CanArgo warrants that as at the date of Completion:



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<PAGE>
4.1.1    it will be the registered and beneficial owner of the Sale Shares and
         that the Sale Shares will be free of any charges, liens or
         encumbrances; and

4.1.2    the Company's only asset will be 50% of the Charter Fund of CSOP and
         that the Company shall at the date of Completion have no liabilities.

4.2      No other warranty, whether express or implied is given by CanArgo to
         the Purchaser.

5        COMPLETION

5.1      Completion of the sale and purchase of the Sale Shares ("COMPLETION")
         shall take place immediately following receipt of the Final Payment by
         CanArgo.

5.2      At Completion, CanArgo shall deliver the following:-

5.2.1    transfers of the Sale Shares duly executed by CanArgo in favour of the
         Purchaser together with the definitive certificates in respect thereof
         in the names of CanArgo;

5.2.2    a written waiver in the agreed form from CanArgo in respect of any
         claims which CanArgo (and any member of CanArgo's group) may have
         against the Company and CSOP as at Completion and releasing the Company
         and CSOP from all and any liabilities which may be owing to CanArgo or
         any member of CanArgo's group by the Company or CSOP;

5.2.3    the resignation referred to in clause 7.2;

5.2.4    resignations of David Robson and Russell Hammond as directors of CSOP

5.3      At Completion, the Purchaser shall deliver a written waiver in the
         agreed form from the Company and CSOP in respect of any claims which
         the Company or CSOP may have against CanArgo and any member of
         CanArgo's group as at Completion and releasing CanArgo and any member
         of CanArgo's group from all and any liabilities which may be owing to
         either the Company or CSOP by CanArgo or any member of CanArgo's group.

5.3.1    The Purchaser shall be responsible for obtaining all consents, waivers
         and approvals to the Acquisition.

5.4      For the purposes of this Clause 5, `CanArgo's group' means any holding,
         subsidiary or associated company CanArgo or any subsidiary or
         associated company of any such holding company.

6        LICENCE

6.1      Subject to Completion taking place CanArgo hereby grants to CSOP a 10
         year licence (subject to clause 6.3) (the "LICENCE") entitling CSOP to
         use the name "CanArgo Standard Oil Products" (the "NAME") solely for
         the purpose of petrol retailing.

6.2      CSOP shall be bound to use the Name in carrying on its business for not
         less than 2 years from the date on which Completion takes place unless
         and until a majority shareholding of CSOP is disposed to a major,
         recognised international petrol retailer.

6.3      There shall be no fee for the first 2 years of the Licence but
         thereafter CSOP shall pay CanArgo on 31st December each year a royalty
         fee of US$10,000 per annum as consideration for the Licence.



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<PAGE>
6.4      CanArgo will have the right to terminate the Licence on demand if
         CanArgo's name is brought into disrepute or for misuse of the Name by
         CSOP or failure to pay any royalty pursuant to clause 6.3.

7        DIRECTORS

7.1      To the extent that it is able, CanArgo shall procure that Dr David
         Robson, Vincent McDonnell and Elizabeth Landles (the "CURRENT
         DIRECTORS") will remain directors of the Company from the date hereof
         until the date of Completion.

7.2      At Completion, CanArgo shall deliver the written resignation of each of
         the Current Directors unless the Current Directors agree with the
         Purchaser to remain as directors of the Company after Completion.

8        ENTIRE AGREEMENT

         This letter constitutes the entire understanding and agreement of the
         parties with respect of the subject matter hereof and supersedes all
         prior and contemporaneous agreements and understandings written or oral
         regarding the subject matter of this letter.

9        CONFIDENTIALITY

9.1      All parties undertake:-

9.1.1    To keep confidential the existence and terms of this letter; and

9.1.2    Not to disclose the same to any other person unless expressly
         authorised by the board of directors of CanArgo save for the purposes
         of:-

         (a)      Seeking legal or accounting advice in relation to its terms;
                  and

         (b)      Disclosing the same to a competent authority or stock
                  exchange, as required by law.

10       FEES, COSTS AND EXPENSES


         The parties shall each bear their own professional and other costs and
         expenses including, without limitation, any taxation associated with
         the Acquisition.

11       ANNOUNCEMENTS

         No announcement (whether internal or external) or press communication
         or release of information concerning this letter or Acquisition in
         connection with the Acquisition shall be made by any party other than
         as agreed between the parties save for any announcement required by
         applicable law or regulatory authority.

12       GOVERNING LAW AND JURISDICTION

12.1     This letter shall be governed and construed in accordance with the law
         of England.



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<PAGE>
12.2     Each party hereby irrevocably submits to the non-exclusive jurisdiction
         of the Courts of England as regards any claim, dispute or matter
         arising out of or in connection with this letter and its implementation
         and effect.

IN WITNESS WHEREOF, these presents consisting of this and the preceding 3 pages
are executed as follows:
SUBSCRIBED for and on behalf of
CANARGO LIMITED
at St Peter Port, Guernsey
on the 14th day
of October 2002
by

/s/Dr David Robson........................   Director

Dr David Robson...........................   Full Name

/s/Elizabeth Anne Landles.................   Director

Elizabeth Anne Landles....................   Full Name

SUBSCRIBED for the said

WESTRADE ALLIANCE LLC by its Attorney under Power of Attorney

dated  October 1-st, 2002

at St Peter Port, Guernsey

on the 14th day of October 2002

/s/Samson Pkhakadze.......................   Attorney

Samson Pkhakadze .........................   Full Name

before this witness

/s/Paul Richmond Davidson.................   Witness

Paul Richmond Davidson....................   Full Name

70 Wellington St..........................   Address

Glasgow...................................


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<PAGE>
                                   SCHEDULE 1

                             DETAILS OF THE COMPANY

<TABLE>
<S>                                     <C>
NAME:                                   CanArgo Petroleum Products Limited

DATE OF INCORPORATION:                  25 August 1998

REGISTERED NUMBER:                      N: 34379

REGISTERED OFFICE:                      PO Box 291, Commerce House Les Banques, St. Peters Port, Guernsey

AUTHORISED SHARE CAPITAL:               L10,000 divided into 10,000 Ordinary Shares of L1.00 each

ISSUED SHARE CAPITAL:                   2 Ordinary Shares of L1.00 each

DIRECTORS:                              Dr David Robson, Vincent McDonnell, Elizabeth Landles

SECRETARY:                              C.M.S. Limited
</TABLE>



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