NEW YORK/TOKYO (Reuters) - Lehman Brothers LEH.N was fleeced out of more than $355 million in a fraud the U.S. investment bank believes was perpetrated by two employees at Japanese trading house Marubeni Corp. 8002.T, according to a person briefed on the matter.

The Lehman Brothers headquarters is seen in New York January 30, 2008. REUTERS/Shannon Stapleton

The fraud may have hit other financial institutions as well, according to the source, who spoke on condition of anonymity.

If Lehman’s arguments are true, the scamsters perpetrated one of the more sophisticated corporate con jobs since Enron set up a fake trading floor to impress analysts. Lehman believes the scam included forged documents and an imposter.

Lehman is trying to recover a loan to a fund headed by Asclepius Ltd -- a now-bankrupt unit of LTT Bio-Pharma Co 4566.T. Lehman had believed the money, supposedly to be used to finance medical leases, was backed by Marubeni.

The bank believes Marubeni is now shirking its obligations to pay back the partnership between Lehman, Marubeni and the fund, the person told Reuters.

Marubeni, which fired the two employees on March 10, said the two employees may have been manipulated by the former president of Asclepius, that Marubeni had not approved the leases and that police are working on the case.

The employees were contractors, spokesman Hirokazu Iwashima said, adding that there was “no involvement by Marubeni as a company.”

Lehman plans to sue Marubeni, spokesmen in Tokyo and New York said. They declined to say how much money it had put into the business or elaborate on what exactly the former Marubeni employees did.

“We are confident in our legal claim which we will pursue until we receive repayment from Marubeni,” said Matthew Russell, Lehman Brothers head of Corporate Communications, Asia-Pacific, in a statement sent to Reuters.

The person briefed in the matter told Reuters that two former Marubeni employees -- Shingo Yamaura and Takuro Nitahara -- convinced Lehman to help finance what it understood were Marubeni’s equipment leases and supply contracts with hospitals. Lehman gave the partnership money in advance to fund initial leases and contracts.

When Lehman sought payment under its deal on Feb 29, 2008, Marubeni said the seals on the contracts had been forged, and refused payment, according to the person briefed on the matter.

Marubeni declined comment on Lehman’s statements, and said it could not give information on people no longer with the trading house or comment on ongoing investigations.

Yamaura and Nitahara were not able to be reached for comment.

Before agreeing to fund the venture, Lehman asked to meet the Marubeni general manager involved. The man Lehman employees met was an imposter, Lehman believes, the source said.

Lehman said in a statement on Saturday, “Lehman Brothers Japan Inc. today confirmed that it is working closely with the authorities to seek full recovery of funds it believes to have been fraudulently misappropriated from transactions in which an affiliate provided financing.”

LTT Bio-Pharma officials were not available for comment.

The company announced on March 19 that bankruptcy proceedings filed by Asclepius were approved by the Tokyo District Court and also announced that Asclepius was suspected of being involved in illegal dealings.

Kyodo News said Asclepius dismissed its then-president on March 7.

A spokesman at the Metropolitan Police Agency declined to comment on ongoing investigations.

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