UPDATE 1-SpongeBob coins among missing Peregrine assets

* Bankruptcy trustee discloses missing coins, gold

* Silver four-coin sets sold for $259 each

* Retail value of missing SpongeBob coins around $20,000

By Ann Saphir

CHICAGO, Sept 7 (Reuters) - Hundreds of SpongeBob SquarePants silver coins thought to be in the possession of Peregrine Financial Group, the bankrupt commodities futures trading firm, have gone missing.

The disclosure that 304 silver coins sporting the image of TV cartoon character SpongeBob SquarePants could not be located was made in a court filing on Thursday by Peregrine Financial's bankruptcy trustee. Thirty-nine ounces of gold were also missing.

Cedar Falls, Iowa-based Peregrine Financial collapsed in July after its chief executive attempted suicide and confessed to having stolen millions in customer assets over two decades.

Compared with the $215 million in customer money that regulators allege were wrongly siphoned from the firm by the CEO, Russell Wasendorf Sr., the value of the missing metals is marginal.

At Friday's prices, the gold would fetch about $66,000; the missing commemorative SpongeBob coins, minted in New Zealand and sold in sets of four, have a total retail value of about $20,000.

Thursday's court filing, which provides rich details on all of Peregrine Financial's known assets - down to a decade-old Apple Inc computer valued at $5 - leaves open the possibility that Peregrine itself may have been the victim of pilfering.

Or that it had a few valuable items misplaced.

The SpongeBob coins were the brainchild of a Peregrine unit called PFG Precious Metals Inc and an Auckland, New Zealand-based minting firm, which began manufacturing the novelty items for the Peregrine unit last year to sell to customers. PFG Precious Metals also sold gold and platinum coins.

Shortly after Wasendorf attempted suicide on July 9, leaving a signed confession of his years-long fraud, the FBI searched the firm's Cedar Falls headquarters and seized a stash of SpongeBob coins worth about $375,000, based on the retail price per set of $259.

Peregrine owns 1,528 sets, according to the bankruptcy court filing's 180-page document that lists assets and some liabilities.

A note added, "2 sets were located in Iowa desks, 1 set is held by Tom Garland in Chicago, and FBI inventoried 1449 sets; so PFG is missing 76 sets."

Garland was the firm's director of precious metals.

Peregrine also owned 172 ounces of gold, but only 133 ounces could be located, according to the filing, which also provided the first details on Peregrine assets and debts since the firm filed for bankruptcy on July 10.

"39 ounces missing," it said.

SpongeBob SquarePants is a cartoon series on the Nickelodeon cable television network, a unit of Viacom Inc.