Lehman Brothers Holdings Inc., the fifth-biggest American securities firm, agreed to pay $222.5 million to resolve a suit filed by investors over the bank’s role as an underwriter for Enron Corp., the bankrupt energy trader, people familiar with the settlement said.

New York-based Lehman, accused of misleading investors in Enron debt offerings stretching back to 1998, won’t admit wrongdoing under the settlement, the people said. Lehman’s board and the University of California Board of Regents, the lead shareholder in the case, must approve the accord, which was negotiated by its lawyers, the people said.

“It’s a pretty good-sized settlement that gives the investors a club for future negotiations,” said a securities law professor at Duke University, James Cox. “It also provides the other big financial institutions who’ve been sued with a good idea of what the settlement threshold may be for this case.”

The settlement would be the largest so far stemming from the 2002 investor suit, which named Citigroup Inc., JPMorgan Chase & Co., and Enron’s other investment banks among the defendants. The settlement amount is equal to about half of Lehman’s $505 million net income for its third quarter, which ended August 31.

Lehman issued debt offerings that contained misleading financial statements about Enron, investors claim. Under American law, the firm’s potential liability is limited to the securities it underwrote, Mr. Cox said. Shareholders and bondholders, who are seeking $30 billion in damages, have accused others banks, such as Citigroup and JP Morgan Chase, of helping Enron commit accounting fraud. The banks denied wrongdoing in court papers.

The settlement process has not been completed, said a Lehman spokeswoman, Hannah Burns, in a statement. “The company believes that such a settlement, if it occurs, will have no impact on the company’s results from operations,” she said.

Trey Davis, a spokesman for the regents, declined to comment on settlement negotiations. California’s university system lost $145 million on investments in Enron, which filed the second largest bankruptcy in American history in 2001.

“The university has been involved in settlement talks and the regents are considering the matter at their board meeting this week,” Mr. Davis said in a statement.

Enron shareholders allege in their suit that the former energy trader disguised billions of dollars in loans as energy transactions and hid debt in off-the-books partnerships.

Four former executives of Merrill Lynch & Co. and two former Enron employees are on trial in Houston, accused of conspiring to boost Enron’s finances artificially by $12 million through a sham sale of energy-producing Nigerian barges to the bank. Prosecutors charge that Enron promised to return Merrill’s investment plus 15%, making the transaction a loan.

Enron filed for bankruptcy protection after it admitted its misstatement of income and restated $586 million in revenue. Its shares lost $68 billion in value from their share-price high in August 2000. The company fired more than 5,000 people.

Enron has won bankruptcy court approval of a plan to sell all its properties and begin paying back creditors about 20 cents on the dollar. After that, the energy company will cease to exist.

Lehman’s shares, which have risen 14% over the last 12 months, fell 12 cents to $79.45 at 9:42 a.m. in New York Stock Exchange composite trading.