The electronics giant, whose PlayStation 2 games console has outsold rivals from Microsoft and Nintendo 3-to-1, announced plans Tuesday for a handheld game player.

The PSP, introduced during a press conference in advance of the Electronic Entertainment Expo (E3) trade show here, would compete to some extent with Nintendo's Game Boy, which has all but owned the portable game market for more than a decade.

But Sony apparently has grander plans than a nice game of Tetris. The PSP will have a screen capable of showing 3D images, stereo sound, USB 2.0 connectivity and a custom processor built on cutting-edge 90-nanometer chipmaking technology.

The device will also use a new media format. The UMD disc is an optical disc about half the size of a DVD or CD and capable of holding 1.8GB of data.

Sony did not offer a projected price for the PSP, but said it plans to release the device late next year, with Ken Kutaragi, president of Sony Computer Entertainment, promising it would be "the Walkman of the 21st century."

Sony also introduced a new accessory for the PlayStation 2, the I Toy. The USB camera will initially be used as a custom game controller, but Sony also expects it to support videoconferencing, live special effects and a host of other uses.

Kaz Hirai, president of Sony Computer Entertainment America, said it is part of Sony's quest to expand the utility of the PlayStation 2. "Don't look to Sony just for leadership in the games space," he said. "Look for us to find the right path to digital entertainment convergence."

Hirai also announced a new PlayStation 2 package. The $199 PlayStation 2 Online Pack will bundle a console with a free Sony network adapter for online play, which sells separately for $40. The package, available in June, will also use the new version of the PlayStation 2 recently introduced in Japan, with support for rewritable DVDs and a quieter fan.