Contracts for pending sales of previously owned homes unexpectedly rose in February, a survey from the National Association of Realtors showed, a rise the group said may be attributed to home buyers taking advantage of a soon-to-expire tax credit.

The Realtors said its Pending Home Sales Index, based on contracts signed in February, rose 8.2 percent to 97.6 from a downwardly revised 90.2 in January.

Analysts polled by Reuters had forecast pending home sales, which lead existing home sales by one to two months, would remain essentially unchanged in February.

Anecdotally, we're hearing about a rise of activity in recent weeks with ongoing reports of multiple offers in more markets, so the March data could demonstrate additional improvement from buyers responding to the tax credit, said Lawrence Yun, NAR chief economist.

First-time home buyers who sign a contract before the end of April, and close the transaction before the end of June, are eligible to receive $8,000 from the government. Buyers who are selling a home and buying a new home are eligible for $6,500.

The housing recovery is weaker in magnitude compared with other recoveries, but it is still recovering, said Kurt Karl, chief U.S. economist at Swiss Re in New York.

The index is 17.3 percent higher than February 2009.

(Additional reporting by Richard Leong; Editing by Neil Stempleman)