WASHINGTON, June 17 (Reuters) – Contracts to purchase previously owned U.S. homes increased more than expected in May, ?though higher mortgage rates and tight supply remained ?constraints for the housing market.

The pending home sales index rose 3.8% last month to 76.8, the highest level since ?last November, the National Association of Realtors said ?on Wednesday. Economists polled by Reuters had ?forecast contracts, which become sales after a ?month or two, increasing 0.8%. Contracts increased in all four regions, soaring ?8.7% in the Northeast and surging 8.1% in the Midwest.