Amid a slowdown in funding for public interest legal work and a downturn in business at private law firms, Simpson Thacher & Bartlett is sending some of its associates to year-long stints at nonprofit organizations.

The New York-based firm has extended the duration of its public interest fellowships from three months to one year, with the expectation that the associates will return to the firm after their service.

Simpson Thacher partner William T. Russell said that the move was not a result of a decrease in work for the associates, but he also said that it “would not surprise” him if the usual associate attrition at his law firm, like others, has declined during the recession. Russell co-chairs the law firm’s pro bono committee.

“It’s really about furthering our public interest initiatives,” Russell said. He added, “We’ve got associates looking to do more.”

The law firm is offering fellowships to 15 associates with one to three years of experience and paying them $60,000 up front. They will not remain employees of the firm while they work for the nonprofit, although they can keep their insurance benefits, Russell said.

The starting salary for Simpson Thacher associates is $160,000. No layoffs have been reported at the 869-attorney firm during the recession, although legal blogs have reported rumors of associate cutbacks there.

Public interest entities — from indigent client services groups and constitutional rights organizations to children’s services programs — have experienced funding declines due to belt-tightening among donors. At the same time, many report that the need for their services has grown because of layoffs and repercussions from the economy’s nosedive.

Meanwhile, law firms have experienced sharp drops in the usual associate departures that they have come to expect from young lawyers, who now are staying put at their firms because of decreased associate demand industrywide.

‘A great idea’

“It’s a great idea” said Jon Lindsey, referring to Simpson Thacher’s move. Lindsey is managing partner of the New York office of Major, Lindsey & Africa, an attorney search firm.

For law firms with idle associates, they can benefit from sending young lawyers off to gain experience in the public sector, he said. Firms also can preserve their reputation by avoiding layoffs, he said.

Extending the duration of the fellowships is an idea that the law firm “has been kicking around for some time,” Russell said. Some 25 to 30 associates have expressed an interest in the option, he said.

Associates can choose which nonprofit organization to work for, and the program is available to associates at all of the law firm’s offices. Joel Henning, a consultant with Hildebrandt International, called a move like Simpson Thacher’s “wonderful.”

“Rather than terminating people whom they like, they get to keep them. Those people are going to have a positive feeling about the firm,” Henning said. Simpson Thacher has eight offices. Its largest, in New York, has about 650 attorneys. It has about 70 attorneys in Palo Alto, Calif., and about 45 in London.

Simpson’s program was first reported on legal blog Above the Law.