US videogame sales extended their decline in February with a 25 percent monthly drop compared with a year ago, according to an industry tracker.

NPD Group said Thursday that total sales of hardware, software and accessories were $810 million in February, down from $1.09 billion 12 months earlier.

Videogame hardware sales were down a whopping 36 percent despite the launch late last year of the new version of Nintendo's Wii console and PS Vita from Sony. NPD said Microsoft's Xbox 360 was the top-selling device for the 19th consecutive month.

But analyst Liam Callahan said much of that decline is being offset by games in other formats, including digital subscriptions and mobile gaming apps.

"These sales figures represent new physical retail sales of hardware, software and accessories, which account for roughly 50 percent of the total consumer spend on games," he said.

Adding in digital format sales, subscriptions, mobile apps and social network games, he said total consumer spending on the sector in February would be around $1.2 billion.

The top selling game in the month was Dead Space 3, a third-person shooter game available on the Xbox, Playstation and PC.