The number of single-family homes and condominiums put under agreement in May increased year-over-year for the first time since December, according to a recent report from the Massachusetts Association of Realtors (MAR).

The number of single-family homes put under agreement in May was up 2.1 percent to 4,760 from 4,663 compared to the same time last year, according to a statement. The number of condos put under agreement in May increased 1 percent to 1,905 units from 1,894 units in May 2010.

"We were fairly confident that we would see an increase in the number of homes put under agreement this May compared to the same time last year," said 2011 MAR President Laurie Cadigan, broker-owner of Barrett & Co. in Concord. "At the same time, we continue to move in a positive direction from April as home affordability remains very high."

A pending sale or a sale "under agreement" is when the buyer and seller agree on the terms of the sale of a home and have a signed purchase and sale agreement, but have yet to close and be recorded as such.