But the launch of its new Playstation system will take place in Japan on 4 March 2000, three months later than expected.

The world's media was present for Playstation 2's unveiling

By missing this year's lucrative Christmas season it gives fresh opportunities to rival Sega, whose Dreamcast console achieved sales of $100m on its first day in US stores last week.

However the overwhelming leader in the games market expects to make up the lost ground by selling one million units within the first two days of the machines hitting Japanese shops.

Playstation 2 is not scheduled to debut in the US and Europe before next autumn.

It had been expected that sales of Playstation 2, priced at 39,800 yen (£228, $368) in Japan, would begin in 1999.

But the company, which holds the number-one position in the $6.3bn a year video game industry, had made no official statements on an exact launch date.

Sixty million Playstation's have been sold

Analysts speculated that the delay may have been caused by Sony's lack of experience in turning out the super-fast chips to be used in the new console.

Although it has been beaten to the punch by relative minnow Sega, Sony hopes to get its new model in the shops before main rival Nintendo's next generation console hits the market before Christmas 2000.

At the launch in Tokyo of the sleek black machines, Sony said it believed Playstation 2 would prove popular with its stereo-quality sound, spectacular graphics and Internet downloads available from 2001.

Sony increasingly depends on its success, with sales of the current Playstation accounting for about 40% of group operating profit in the year to March.

Nintendo's dolphin launch

Although the Playstation is dominant, with 60 million sold, the market is still volatile, as Tokyo-based Sega has learned.

Its $199 Dreamcast machine, the first to feature 128-bit computer chip technology and Internet capability, is seen as make or break after its predecessor, the 1995 Sega Saturn, flopped badly.

Back then, the company saw its US market share slide to 1% from 50% in the early 1990s.

Kyoto-based Nintendo, the world's second-largest video game player maker, plans to begin selling a next-generation game console, the Dolphin, in time for the 2000 Christmas shopping season.

But even with a year's lead in the US, analysts expect Sega to be little more than an minor irritant to rivals Sony and Nintendo.

Fog of cold breath

In the US the current Playstation has around 60 to 70% of the market for larger video game consoles, with most of the rest going to the Nintendo 64 console.

Sony hopes that many games players will be willing to wait for Playstation 2 because it will be the first "backwards compatible" console - allowing existing Sony games to be played on it.

Ken Kutaragi, president of Sony Computer Entertainment said: "We hope a new type of entertainment will be created. We would like to offer entertainment content beyond people's imagination."