The total dollar amount of settlements of U.S. class-action securities lawsuits rose 39 percent in 2009 and could rise further this year as cases stemming from the financial crisis wind on.

There were 103 settlements totaling $3.83 billion last year, up from 97 settlements totaling $2.75 billion in 2008, according to a study released on Wednesday by Stanford Law School and Cornerstone Research.

Two settlements accounted for 39 percent of last year's total: $925.5 million paid by UnitedHealth Group Inc over the backdating of stock options, and $586 million to end eight years of litigation against hundreds of defendants over initial public offerings.

The median accord was unchanged from 2008, at $8 million.

Experts have said settlement totals should rise as cases tied to the 2008 stock market decline and credit crisis are addressed. They said such cases may fare better when plaintiffs show that companies intended to defraud or deceive them, not simply that they guessed wrong about the economy or markets.

The better cases are when there is a whistleblower, or a parallel investigation by regulators in which specific facts come out that suggest a company acted internally in a way that contradicted what it told the market, said Stephen Rodd, a partner at Abbey Spanier Rodd & Abrams LLP in New York. They may also involve accounting issues where companies might have played with their books to make them look better.

Rodd's firm represented the lead plaintiff in a lawsuit that resulted in a January jury verdict finding French media company Vivendi SA liable for misleading investors about its financial condition prior to a $46 billion, three-way merger with Seagram Co and Canal Plus nearly a decade ago.

Last year's settlements were well below a record $18.3 billion in 2006, including $7.2 billion over Enron Corp.

Other busy years were 2005, when the $10.02 billion of settlements included $6.2 billion related to WorldCom Inc, and 2007, when the $7.36 billion of settlements included $3.2 billion for Tyco International Ltd.

Joseph Grundfest, director of Stanford Law School's Securities Class Action Clearinghouse, said recoveries in 2009 tended to be higher when large public pension funds led lawsuits, the U.S. Securities and Exchange Commission pursued related civil charges, or accounting violations were alleged.

Institutional investors were lead plaintiffs on 65 percent of the settlements, the highest percentage since the 1995 federal reform of class-action litigation, which included who could serve as lead plaintiffs.

According to the study, the law firm Coughlin Stoia Geller Rudman & Robbins LLP handled 26 percent of last year's settlements, more than any other firm.

Bernstein Litowitz Berger & Grossmann LLP has the highest median settlement as a percentage of estimated damages, 4.2 percent, among the five law firms with the most settlements.

(Reporting by Jonathan Stempel; Editing by Matthew Lewis, Gary Hill)