The New York office of the Federal Bureau of Investigation is probing allegations that Arochem Corp., a Stamford, Conn.-based oil trading and refining company, defrauded banks here, an FBI spokesman said.

Sources close to the investigation said a focus of the bank fraud probe is Arochem's activity in trading energy futures contracts on the New York Mercantile Exchange. One source said the probe specifically involves the company's "assurances to make good on contracts."Spokesman John Sennett, of the FBI's New Haven, Conn., office, said the N.Y. office's undertaking is a parallel probe to the New Haven office's investigation into allegations of wire fraud by principles of Arochem, whom he wouldn't identify. According to the FBI, "Wire fraud" is a broad term that covers fraudulent activity in which telephone lines were involved, including telephone calls, computer transmissions and telefaxes.

Mr. Sennett said the FBI investigation, which also involves the Internal Revenue Service, has been under way since 1990.

Contrary to comments two weeks ago, Mr. Sennett said "It is not anticipated that the investigation will be concluded in the very near term." Two weeks ago, Mr. Sennett said the U.S. Attorney's Office in Bridgeport, Conn., was expected to present the case soon to a federal grand jury in the state.

As reported, Gregory Classon, Arochem's general counsel, confirmed the company's board of directors suspended its president, Will Harris, and chief

financial officer, V.J. Dispenza; hired off-duty police to bar them from the company's headquarters in late December, and said the action was related to the FBI probe.

Arochem owns an 80,000-barrel-per-day refinery in Ponce, Puerto Rico, which Mr. Classon said two weeks ago has been closed for turnaround and would reopen ''very shortly."

The company has also been a sizable player in trading energy futures contracts, specifically, crude oil, on the Nymex, sources in the N.Y. oil trading community said.

In recent years, Arochem traded about 1,000 contracts a day, trading sources said, noting that the company's Nymex activities have dropped off noticeably in recent months. Arochem is not a member of Nymex, Mr. Classon and a Nymex spokeswoman said earlier.

The Nymex spokeswoman also said that as a matter of policy, the exchange wouldn't comment on whether Nymex officials have been questioned by federal investigators. Arochem was a topic of market talk in early October, when the company was said to have a significant short position in November crude contracts and needed to buy up contracts to cover its position, according to trading sources.

At that time, Mr. Classon refuted the market talk. "We're a private concern and I'm not privileged to go into details with you," he said. "But I can say that our house is in order and we are on a sound footing. I hope whatever rumors you're hearing are taken as just that."

Market traders said at that time that Arochem was apparently having difficulty making margin calls for its position, but that the situation was eventually rectified. Market sources said Arochem eventually was able to make its margin calls by spreading business among various clearing members of the exchange.