Pending sales of existing U.S. homes unexpectedly rose in June from May and rose sharply from a year ago, data from a real estate trade group showed on Thursday.

The National Association of Realtors Pending Home Sales Index, based on contracts signed in June, was up 2.4 percent to 90.9 from 88.8 in May. The index was up 19.8 percent from a year ago.

Economists polled by Reuters ahead of the report were expecting pending home sales to fall 2.0 percent.

The association's senior economist Lawrence Yun said the latest monthly reading shows tight credit and economic uncertainty is still constricting the market.

The best way to ensure a more solid recovery in housing is to simply return to normal, sound credit standards so more creditworthy home buyers can get a mortgage, he said.

(Reporting by Margaret Chadbourn; Editing by Neil Stempleman)