EXHIBIT 10.6

                                February __, 2002

Natexco Corporation
3255 Norfolk Road
Victoria, British Columbia
Canada V8R 6H5

       Re:  LOCK-UP OF SHARES

Ladies and Gentlemen:

       Reference is made to that certain Subscription Agreement dated as of
______________, 2002 (the "SUBSCRIPTION AGREEMENT"), by and between Pashleth
Investments Ltd., as the subscription agent acting on behalf of Natexco
Corporation (the "COMPANY") and the undersigned (the "UNDERSIGNED"), pursuant to
which the Undersigned subscribed for ______________ shares of common stock of
the Company (the "COMMON STOCK") for an aggregate purchase price of
$______________, in anticipation of the contemplated merger (the "MERGER") of
the Company's wholly-owned subsidiary Diomed Acquisition Corp., with and into
Diomed, Inc.

       To induce the Company to enter into the Subscription Agreement, the
Undersigned hereby agrees that for one hundred eighty (180) days following the
later of (a) the closing of the Merger or (b) the effective date of the Merger;
the Undersigned will not (i) offer, pledge, sell, hypothecate, contract to sell,
sell any option or contract to purchase, purchase any option or contract to
sell, grant any option, right or warrant to purchase, lend, or otherwise
transfer or dispose of, directly or indirectly, any shares of Common Stock or
any securities convertible into or exercisable or exchangeable for Common Stock
or (ii) enter into any swap or other arrangement that transfers to another, in
whole or in part, any of the economic consequences of ownership of Common Stock,
whether any such transaction described in clause (i) or (ii) above is to be
settled by delivery of Common Stock or such other securities, in cash or
otherwise. This foregoing lock-up shall be of no force and effect in the event
that the Company is not listed on the American Stock Exchange within 60 days of
the date hereof.

       Notwithstanding the foregoing, the Undersigned may transfer shares of
Common Stock (i) as a bona fide gift or gifts, provided that the donee or donees
thereof agree in writing to be bound by the restrictions set forth herein, or
(ii) to any trust for the direct or indirect benefit of the Undersigned or the
immediate family of the Undersigned, provided that the trustee of the trust
agrees in writing to be bound by the restrictions set forth herein, and provided
further that any such transfer shall not involve a disposition for value. For
purposes of this letter, "immediate family" shall mean any relationship by
blood, marriage or adoption, not more remote than first cousin.

                                              Very truly yours,

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                                              Name:

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                                              Address