NEW YORK, June 27 (Reuters) -- U.S. regulators are on pace this year to settle the fewest insider trading cases in at least a decade, a new study shows, as they choose to battle high-profile defendants.

The U.S. Securities and Exchange Commission reached just 25 insider-trading settlements from October 2010 to March 2011, the first half of its fiscal year, the NERA Economic Consulting study released on Monday shows.

That puts the SEC on pace for a full-year total of 50 insider-trading settlements. That would be down from 74 a year earlier, and the fewest since the Sarbanes-Oxley law strengthening corporate governance took effect in 2002.

"It is consistent with the idea that the SEC is directing its enforcement resources toward higher-profile cases," said James Overdahl, a NERA vice president and former SEC chief economist who co-wrote the study.

"That would be consistent with a strategy of focusing on deterrence by bringing cases that would send a message," he said. "There may be an issue of trying to deter others from wrongdoing by litigating rather than settling, but it is a risky strategy because the SEC has to be sure it prevails."

An SEC spokesman was not immediately available to comment.

The SEC can bring civil, not criminal cases. It typically seeks to have insider trading defendants pay fines, give up illegal profits and agree not to commit further wrongdoing.

Among the insider trading cases it has yet to resolve is a lawsuit against Galleon Group hedge fund founder Raj Rajaratnam, who was convicted by a federal jury on May 11 of criminal insider trading charges.

The SEC also charged former Goldman Sachs Group Inc director Rajat Gupta with tipping Rajaratnam about the bank's earnings and a pending $5 billion investment from Warren Buffett's Berkshire Hathaway Inc. Gupta's lawyer has called those charges totally baseless.

The SEC also is investigating David Sokol, a former top Berkshire executive, once widely seen as Buffett's heir apparent, a person familiar with the matter has said.

He made a $3 million profit on Lubrizol Corp while having talks with bankers about the chemicals company, which Berkshire later decided to buy.

Sokol's lawyer has said his client honored his fiduciary duties, and never broke the law or any Berkshire policy.

Among those to settle in the six months covered by the study were Joseph Nacchio, the now imprisoned former chief executive of Qwest Communications International Inc.

Overall, the SEC is on pace to settle 688 cases with companies and individuals in its current year, up from 681 a year earlier. These include charges such as misrepresenting financial statements, bribery and insider trading.

The pace of company settlements rose 43 percent over the half-year period, NERA said. There have been 114 such settlements, compared with 160 in all of the prior year.

"The SEC has to be careful about penalizing companies," Overdahl said. "Shareholders are often the victims of a fraud, and allowing companies to use shareholder money to make those cases go away can be seen as penalizing shareholders twice."

Last week, the SEC reached a $153.6 million settlement with JPMorgan Chase & Co to resolve charges that the bank fraudulently hid from investors that a hedge fund helped shape, and then bet against, complex mortgage securities they bought.

(Reporting by Jonathan Stempel)