Sales rose 54 percent to $1.7 billion in June 2008 on sales of new releases "Guitar Hero World Tour and "Metal Gear Solid".
June sales of the $249.99 Wii declined 46 percent to 361,700 players in June, NPD said. Sony's PlayStation 3, priced from $399.99, slid 59 percent to 164,700 units. Sales of Microsoft's Xbox 360, which starts at $199.99, increased to 240,600.
The drop for the month was the largest since a 41 percent decline in September 2000, according to NDP data.
The top-selling game in June was Electronic Arts 's "Fight Night Round 4," which sold a combined 471,000 copies for Xbox 360 and PlayStation 3.
Bobby Kotick, chief executive of Activision Blizzard, have argued console makers should cut prices to reverse the industry slide. Earlier this month, he had pressured Sony to cut the price of the PS3, saying his company may shift resources to rival systems.
Howard Stringer, Sony's chairman and chief executive officer, said this month there are no plans to cut the PS3 price because the console isn't profitable. He added that Sony was losing money for each PS3 console made.