Japan's Sony Corp plans to sell a smaller and lighter PlayStation Portable (PSP) handheld game machine later this year, according to video game websites which cite what they say is Sony's own promotional video clip.

The video clip, which game websites including IGN say was first distributed through Sony's online game information distribution service for paying U.S. subscribers, has been posted on YouTube. For the YouTube link, click http://www.youtube.com/watch?v=ObElhJIcOKE&feature=related

The new device, dubbed the PSP Go, is 43 percent lighter than the current model and comes with a 3.8-inch display, compared with a 4.3 inch screen now, according to the video clip on YouTube.

A spokesman for Sony's game unit, Sony Computer Entertainment declined to comment on the video clip, saying that any announcement on the PSP will be made at the E3 video game trade show that starts on Tuesday in Los Angeles.

According to the video clip, the PSP Go will go on sale this autumn, although the current model, the PSP 3000 will remain in the market.

The newer model's key pad slides out from below the screen, the clip shows. With the PSP 3000, the keys are placed on either side of the screen.

Sony aims to sell 15 million units of the PSP in the financial year to March, up from 14.1 million units a year earlier. The PSP competes with Nintendo Co Ltd's DS.

Shares in Sony rose 2.6 percent to 2,560 yen, outperforming the Nikkei average, which gained 1.6 percent.

(Reporting by Kiyoshi Takenaka; Editing by Edwina Gibbs)