NEW YORK - Lehman Bros. Holdings on Monday confirmed fears on Wall Street that the credit crisis isn't quite over, and it left investors to wonder whether other major investment banks face the same set of risks.

The nation's fourth-largest investment bank said wrong-way trading moves and risky mortgage-backed securities plunged it into a nearly $3 billion second-quarter loss. It marks the first time Lehman was unable to post a profit since going public in 1994.

Its stock fell nearly 9 percent and helped drive a broad sell-off in bank and brokerage shares.

Lehman's top executives, who have repeatedly assured investors that their books were safe, will fund the firm's survival by raising $6 billion of fresh capital. It is a move many of Lehman's competitors have already been forced to make.

The announcements, made before Monday's official release date of Lehman's results, were an attempt to calm a market still badly shaken by the near collapse of Bear Stearns in March. Analysts were disappointed that Lehman's loss was much deeper than they expected, and felt it could have an impact on rivals.

"There is a broader element to all this," said David Trone of Fox-Pitt Cochran. "Management considered this to be an aberration, but I think you'll see similar results in form and structure, just the magnitude will be smaller."

Sanford C. Bernstein analyst Brad Hintz, a former chief financial officer of Lehman, said one concern is the $130 billion of mostly residential and commercial real estate assets the firm sold during the quarter. Those sales triggered billions of dollars of gross mark-to-market adjustments - or accounting changes to the value of assets - since the beginning of last year.

He believes that if those prices are deeply discounted, it would set a precedent that could hurt rivals such as Merrill Lynch & Co., Morgan Stanley and Goldman Sachs Group. Those companies have also had write-downs of mortgage-backed assets, with Merrill taking a heavy enough hit that it lost its chief executive officer. Goldman is thought to be the strongest of the Wall Street companies.

Further, Lehman's investments to hedge against troubled assets on its books backfired, and Chief Financial Officer Erin Callan said they "were significantly impacted" during the past few months. She said the highest point of the market's disruption this year was in March, but conditions have eased since then.

Lehman said it expects to lose $2.87 billion, or $5.14 a share, for the period ended May 31, compared with the $1.3 billion, or $2.21 a share, it made in the year-ago period.

Analysts had expected the company to report a loss of just 22 cents share for the period, according to Thomson Financial.

CEO Richard Fuld said he was "very disappointed" in the quarterly results. However, he said he thinks the additional capital, raised through an offering to yet unnamed investors, will help keep the company whole amid continued market turmoil.

There had been market speculation that Lehman was seeking outside investors to offset losses during the quarter and fortify its balance sheet.

Some analysts felt the firm's balance sheet was the closest of all the Wall Street firms to Bear Stearns, which narrowly avoided bankruptcy in March through its government-sponsored sale to JPMorgan Chase & Co.

Lehman is expected to raise capital by selling to mostly American investors $4 billion of new common shares and $2 billion of three-year mandatory convertible preferred stock. The convertible stock is required to be turned into common shares by the end of the three-year period.

The firm was under pressure after David Einhorn, who runs the hedge fund firm Greenlight Capital, vocally and publicly raised questions about Lehman's earnings during the first quarter.

He said the company has not disclosed all of its losses, and felt Monday's announcement was only the start.