NEW YORK (AP) – A market research group says U.S. video game retail sales declined for the second month in a row in April.

A big culprit is last year’s launch of the blockbuster “Grand Theft Auto IV,” which hit store shelves on April 29, 2008 and raked in more than $500 million within a week.

That and the launch of Nintendo’s “Mario Kart Wii,” another very popular game, was hard to follow up this year.

NPD says total game sales slumped 17 percent to $1.03 billion. Software sales declined 23 percent to $510.7 million, more than some analysts expected.

AP-ES-05-14-09 1907EDT