WASHINGTON - Pending home sales rose in May for the fourth straight month, spurred by low prices and a first-time homebuyers tax credit, fresh evidence that the housing sector may be recovering.

The National Association of Realtors said Wednesday that its seasonally adjusted index of pending sales increased by 0.1 percent in May to 90.7. Analysts expected no change, according to Thomson Reuters.

Although the increase was small, it followed a 7.1 percent jump in the index in April.

"The pronounced increase in April and the fact that May sustained this rise does indicate that actual existing home sales are poised to rise in the coming month or two," said Joshua Shapiro, chief U.S. economist for economic forecasting firm MFR Inc., in a note to clients.

The index, which tracks signed contracts to purchase previously occupied homes, is considered a barometer for future home sales. Typically there is a one- to two- month lag between a sales contract and a completed deal.

The index is now 6.7 percent higher than in May 2008, when it was 85. The last time it increased for four straight months was in October 2004, the NAR said.

Separately, the volume of mortgage applications to purchase a home is effectively flat over the past four weeks, the Mortgage Bankers Association said Tuesday.