Sony said on Thursday it would stop shipments of PlayStation 3 models with 20- and 60-gigabyte (GB) hard disk drives in Japan this month, focusing instead on the 40-GB model.

Sony is pinning its hopes on the cheaper PS3 with a 40-GB hard disk drive that was introduced in Japan in November last year in an attempt to better compete with Nintendo's more affordable Wii video game console.

Unlike the two original versions, which were launched in November 2006, the newest PS3 model does not play games designed for the PlayStation 2, has two high-speed USB ports instead of four and has no super audio CD system.

It was introduced with a price tag of 39,980 yen (364 dollars), compared with a reduced price of 44,980 yen for the standard 20-GB hard disk drive PS3. It is still costlier than the Wii, which retails for 25,000 yen.

The move comes as rival Nintendo continues to enjoy strong demand for the Wii, known for its motion-sensitive controller, outselling the PS3 three-fold in its domestic market last year, according to a recent survey.

Sony also expects to make profit out of the PS3 sales for the first time in 2008.