Nintendo Co Ltd plans to launch a new version of its Wii Fit home exercise game this autumn, aiming to help boost sluggish sales of its Wii console in Japan, the Nikkei business daily reported on Sunday.

Called Wii Fit plus, the new version will allow users to compete with friends and family over the Internet to lose weight and other activities, the newspaper said, without citing sources.

Nintendo will also launch a new version of its popular Mario game series in the second half of 2009, the Nikkei said.

A spokesman for Nintendo declined to comment.

Nintendo has weathered the global recession relatively well, with its Wii game console outselling Microsoft's Xbox 360 and Sony's PlayStation 3 since its 2006 launch.

But sales have slowed in recent months due to a scarcity of strong new games.

Analysts and other industry watchers expect Nintendo to unveil a lineup of new software titles at the E3 videogame trade show that starts on Tuesday in Los Angeles.

The Wii Fit game features a shoulder-width balance board that senses shifts in posture. It can be used to monitor weight and for a variety of games and exercises.

Wii Fit plus will be more precise in its measurements, allowing for more accurate monitoring of one's health, the Nikkei said.

(Reporting by Kiyoshi Takenaka and Hideyuki Sano; Editing by Bill Tarrant)