San Francisco ? Canadian Imperial Bank of Commerce agreed Tuesday to pay $2.4 billion to Enron investors who had sued the banking company for its part in the massive accounting fraud that led to the collapse of the failed energy giant.

The settlement with Toronto-based CIBC is the largest single action so far on behalf of Enron stock and bond holders, and brings the total payments in the case to about $7 billion, making this the biggest class-action recovery ever.

William Lerach, the securities lawyer representing the University of California Board of Regents, the lead plaintiff in the case, said settlements with other defendants were expected.

“This settlement demonstrates that the university’s strategy of aggressively pursuing the defendants is working,” Lerach said in a prepared statement.

“We continue to pursue other defendants, including other banks that have been charged with knowingly participating in the scheme to defraud Enron investors,” he added. “Beyond today’s agreement, the lawsuit continues to proceed very satisfactorily and further large recoveries are anticipated.”

The settlement has been approved by CIBC directors and is subject to approval by the UC Regents and the court, according to a release by the University of California.

The class action covers about 50,000 investors who owned Enron securities between September 1997 and December 2001. With the CIBC settlement, the amount of money available to Enron investors now exceeds the $6.1 billion that Wall Street forked over to WorldCom investors in a similar suit.

The latest agreement comes after a similar $2.2 billion settlement with JPMorgan Chase Co. and a $2 billion agreement with Citigroup was reached in June.

Other firms including Bank of America Corp. and Lehman Brothers Holdings Inc., along with Andersen Worldwide, Enron’s outside directors and former vice chairman Ken Harrison already have settled for a combined $491.5 million.

Remaining defendants in the class-action suit include Barclays PLC, Credit Suisse First Boston, Merrill Lynch & Co., Toronto Dominion Bank, Royal Bank of Canada, Deutsche Bank AG and the Royal Bank of Scotland. In addition, the lawsuit names Goldman Sachs Group Inc. over its role as an underwriter of Enron securities.