WASHINGTON (AP) -- Americans signed more contracts to buy previously occupied homes in May, matching the fastest pace in two years. The increase suggests home sales will rise this summer and the modest housing recovery will continue.

The National Association of Realtors says its index of sales agreements increased to 101.1 last month from 95.5 in April. That matches March's reading, the highest since April 2010, when a home-buying tax credit boosted sales.

A reading of 100 is considered healthy. The index is 13.3 percent higher than it was a year ago. It bottomed at 75.88 in June 2010, after the tax credit expired.

Contract signings typically indicate where the housing market is headed. There's a one- to two-month lag between a signed contract and a completed deal.