NEW YORK – Its future in jeopardy and options dwindling, Lehman Brothers scoured Wall Street on Thursday for a financial lifeline. Top executives contacted banks and rival investment houses about a possible deal to buy the company, bankers and industry executives close to the situation said.

The fourth-largest U.S. investment bank, which had tenaciously resisted putting itself up for sale, finally relented after a free-fall in its stock price and growing doubts about whether other financial institutions would continue to do business with it, according to these officials. They asked not to be named because they are not authorized to comment publicly.

The Washington Post reported late Thursday that the Treasury Department and the Federal Reserve are arranging a sale through a consortium of private firms. It said the deal has not been finalized, but quoted unnamed sources as saying it could be announced this weekend.

Government officials who asked for anonymity because of the sensitivity of the ongoing discussions cautioned that a number of options were still being explored and that no decisions had been reached on how any deal to rescue Lehman would be structured.

Randy Whitestone, a spokesman for Lehman, declined to comment.

Bank of America Corp., Japan’s Nomura Securities, France’s BNP Paribas, Deutsche Bank AG and Britain’s Barclay’s Plc also have been mentioned this week as potential buyers.

Goldman Sachs Group Inc., which also was being talked about as a potential buyer, is not interested, according to an industry official who ask not to be named.

Lehman’s losses soared to almost $7 billion in the last two quarters alone, primarily because of wrong-way bets on mortgage securities and other risky investments.

It’s not alone. Global banks have lost more than $300 billion since the subprime mortgage crisis spread to the credit markets one year ago. And the International Monetary Fund has suggested total losses globally could hit $1 trillion.

Lehman Brothers hunted for months for a deep-pocketed investor to pump fresh capital into the firm, a move that would help restore confidence and replenish its broken balance sheet. Some analysts said Lehman was asking too high a price, others guessed that potential investors found too much risk on its books in the current environment.

Lehman CEO Richard Fuld tried to assuage nervous investors on Wednesday by announcing a plan to sell a 55 percent stake in its prized investment management business and spin off its commercial real estate holdings into a publicly traded company.

Fuld cast a wide net for potential investors, bankers and executives said, including stepping up talks with private equity firms such as Kohlberg Kravis Roberts & Co. and Bain Capital.

But analysts increased their criticism of Fuld on Thursday for not naming a potential buyer of its investment management unit, which includes Neuberger Berman, and because they said Lehman would need to finance the real estate spinoff itself. Lehman’s shares skidded $3.03, or 42 percent, to $4.22. That’s down more than 94 percent from their 52-week high of $67.73.

“We believe some type of capital raise or transaction must be consummated quickly to improve confidence in Lehman,” said Standard & Poor’s financials analyst Matthew Albrecht.

Fuld made a name for himself on Wall Street in the late 1990s when he led Lehman through a capital crisis after the failure of hedge fund Long-Term Capital Management.

Despite a dwindling set of options, Lehman Brothers had some advantages that rival Bear Stearns did not before it collapsed in March and was sold to JPMorgan Chase & Co. in a deal backed by the Fed.

Investment banks now can cover short-term funding needs by borrowing directly from the Fed. That option previously was only accessible to commercial banks.

There was no evidence that Lehman had done that, however, in the Fed’s weekly report Thursday on borrowing through its emergency lending program. Commercial banks had averaged $19.8 billion in daily borrowing over the past week. Investment firms took a pass.