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                                                                    EXHIBIT 10.2
June 26, 2000

GENETRONICS, INC.
11199 Sorrento Valley Road
San Diego, CA 92121
Attn: Markus Hofmann, Controller

Dear Mr. Hofmann:

This letter is to confirm that Union Bank of California, N. A. ("Bank") has
agreed to extend the maturity date of the Trade Credit Facility ("Facility")
granted to GENETRONICS, INC. ("Borrower") in the principal amount of TWO MILLION
AND NO/100 DOLLARS ($2,000,000.00) originally made under a certain Trade Credit
Agreement dated AUGUST 19, 1999, as amended from time to time, and Clean Advance
and Trade Finance Notes dated AUGUST 6, 1999 as amended from time to time
(collectively, the "Agreements"). Copies of the notes are attached.

The maturity date of the FACILITY is hereby extended to SEPTEMBER 29, 2000 ("New
Maturity Date") and each related letter of credit expiration date and/or trade
advance maturity date in the Agreements shall be extended to a date which
follows the New Maturity Date by the same number of days as the original
expiration date and/or maturity date followed the original maturity date. The
Agreements shall be deemed modified as of the date of this letter to reflect the
New Maturity Date.

All other terms and conditions of the Agreements remain in full force and
effect, without waiver or modification. This extension is further conditioned
upon Borrower's continued payment of (i) interest as provided in the Agreements,
and (ii) any principal instalments which Borrower was obligated to make prior to
this extension.

Each advance request, or Borrower's continued payments of principal or interest
on the outstanding balance of any term loan, constitutes Borrower's warranty
that no event of default as defined in the Agreement and no condition, event or
act which, with the giving of notice or the passage of time or both, would
constitute such an event of default, shall have occurred and be continuing or
shall exist.

BANK HAS NOT COMMITTED TO MAKE ANY FURTHER EXTENSION OF THE MATURITY DATE, OR TO
RENEW THE FACILITY BEYOND THE NEW MATURITY DATE. ANY FURTHER EXTENSION OR ANY
RENEWAL REMAINS IN THE DISCRETION OF BANK. Finally, the extension of the
maturity date provided herein does not constitute a waiver by Bank of any
rights, remedies, benefits or powers belonging to or accruing to Bank under the
terms of the Agreements for the default(s) set forth above or for any further
default with respect to the same provision(s) or any other provision of the
Agreements. IF YOU HAVE ANY QUESTIONS, PLEASE CONTACT ME AT (858) 552-2051.

This letter replaces the previous extension letter dated June 23, 2000.

UNION BANK OF CALIFORNIA, N. A.

By:  /s/ Kenneth Sluder
   ----------------------------------------
   Kenneth Sluder, Vice President