Nintendo launched its Wii console in Japan on Saturday, making it the third country to see the device on sale after it was launched in the US and Canada on November 19.

About 400,000 consoles are being supplied to Japan for the launch, which is more than four times the number of PlayStation 3 consoles available when that machine went on sale November 11. Combined with the more than 600,000 Wii consoles sold in North America, the Japan launch will push Wii sales over the million mark.

It also virtually assures the Wii a position as the top-selling next-generation console in Japan to date. Sony Computer Entertainment is struggling to supply enough of its PlayStation 3 consoles, and Microsoft's Xbox 360 has been suffering from low sales.

Many electronics retailers opened their doors at 7 am to put the Wii on sale, and long lines had formed at the shops from the day before. More than 2,000 people were waiting outside the Bic Camera store in Tokyo's Yurakucho, according to an estimate by store staff. The retailer was confident that all would be going home with a Wii on Saturday.

The Wii has been drawing positive reviews over the last few weeks. While it lacks the high-definition graphics present on the rival PlayStation 3 and Xbox 360 consoles, the Wii has an innovative wireless controller (nicknamed the Wii-mote) that includes motion sensors.

The controller lets gamers interact with software through natural movements. For example, in a tennis game the Wii-mote is swung like a racket, and in a boxing game it's thrown like a punch. Hold the remote in your hand and simulate bowling a ball, and you've got the hang of the bowling game.

The Wii-mote is the centerpiece of Nintendo's attempt to expand the market for consoles beyond core gamers. The company believes that by offering a controller that isn't intimidating for non-gamers it will make the Wii more attractive to them. The strategy appears to be working. The Wii has enjoyed positive reviews from many media outlets over the past few weeks, and the people in line on Saturday morning to buy the Wii were a much more varied group than those queuing three weeks earlier for the PlayStation 3.

At ¥25,000 (US$215) the Wii is also half the price of the cheapest of the two PlayStation 3 versions on sale, and that's also helping sales.

While Nintendo will initially enjoy better sales thanks to greater supply, the true test for the Wii will probably come in 2007 when the launch hype has died down and both the Wii and PlayStation 3 consoles are plentiful. A slew of new software titles for both new consoles and the Xbox 360 are due out next year, and they will help determine the long-term popularity of each platform.

The Wii is due on sale in Australia on Thursday and will hit Europe on Friday.