A former U.S. Treasury official representing foreign investors said to be from the Middle East made a surprise offer yesterday to buy three New York City hotels from the bankrupt Penn Central Railroad for $50 million.

The bid - for the Barclay, Biltmore and Roosevelt hotels - came from attorney Gerald L. Parsky, assistant secretary of the treasury for international affairs in the Ford and Nixon administrations.

Parsky made his unexpected offer in federal bankruptcy court in Phildelphia. The court was considering a request from trustees of the bankrupt railroad to sell the hotels to the Loews Hotel chain for $45 million.

Parsky petitioned the court to delay the sale, saying he had clients with a higher offer, then surprised even Penn central lawyers by topping Loew's offer by $5 million.

The new bid lead Judge John Fullam to delay action on the Loew's deal and order the trustees to consider Parsky's proposal.

Parsky told the court he was making the offer for Biltmore Hotel Associates, a partnership of the present management of the hotels and a group of foreign investors. Parsky would not disclose the names or nationalities of his clients.

The bidders were indentified as a group of Arab and Iranian investors by David Mizrahi, editor or MidEast Report, a New York-based newsletter on business in the Middle East.

Parsky did not challenge that identification in when he was interviewed after returning to Washington, but said, "The indentities of my principles have purposefully been kept confidential. I explained that in court."

The three midtown Manhatten hotels are among the most valuable assets of the Penn Central. Money from their sale will go to pay off the hundreds of creditors of bankrupt line. Although the bidding had formally closed months earlier, the prospect of getting an additional $5 million for the creditors lead the court to permit the belated offer, a source close to the railroad said.

The Barclay, with 796 rooms, is at 111 E. 48th St., the 900-room Biltmore is at Madison Ave. and 43rd St., and the 1100-room Roosevelt is at Madison and 45th.

The hotels have been run for the Penn Central by a management firm called Realty Hotels Inc. that is headed by Brian Corbell.

Corbell, Parsky said, has formed a company called Baltimore Hotel Enterprises, which in turn formed a partnership with a Netherlands Antilles company, Halad International, N.V. It was that partnership, Baltimore Hotel Associates, which bid for the properties.

Parsky said Corbell's role would be to operate the hotels for the foreign investors, who he said, have no intention of being involved in the management of the business.

"They are purely passive investors, they are not going to be involved in any way in operations of the hotels," added the Washington lawyer.

His clients were offered the investment opportunity by Corbell, who had earlier bid for the hotels with another group, he said.

Parsky, 35, last April joined a major Los Angeles law firm, Gibson Dunn and Crutcher, and opened its Washington office. He was an attorney with Mudge, Rose, Guthrie and Alexander, former President Nixon's old law firm in New York, and came to Washington as special assistant to an undersecretary of the treasury. In 1973 he became executive assistant to Secretary William Simon, serving with him at the Treasury and the Federal Energy Office before being named assistant Secretary of the treasury, also under Simon.

Parsky's specialities at Treasury were international trade and foreign investment in the United States.