RETAILERS are expecting the launch of Sony’s PlayStation Portable (PSP) on September 1 to be an instant sellout because demand has already begun to outstrip supply.

More than 150,000 machines will be available in Britain on launch day, more than double the biggest launch in this country so far of a games console, thought to be the Nintendo DS.

One retailer said: “Stock will be very tight at the launch. It is clear that demand has been very high.”

Retailers including Dixons, HMV and Game are understood to have stopped taking pre-orders of the PSP for collection on the launch day.

A spokeswoman for WH Smith said that it would be able to fulfill 95 per cent of its pre-orders on the launch day. “The remaining customers are fully aware that they are not guaranteed to receive their PSP on the launch date, but we have held some back for those customers wanting to come into stores,” she said.

Many retailers have set aside stock to go into stores on the day, but one admitted: “It will be a very limited number.”

Retailers said that they were “satisfied” with their allocation of games hardware from Sony, which has broadened its distribution on launch day to include supermarkets such as Tesco and Asda as well as the specialist stores. Sony hopes to sell one million PSPs by Christmas A spokesman for Sony said: “Clearly, demand is outstanding and obviously we would like to satisfy that. We have very ambitious sales targets and will do our best to get stock in as soon as we can.”

Game, the specialist retailer, which is opening 250 of its 400 stores at midnight on Thursday, said: “A lot of PSPs will be arriving in stores this week on our launch, but the vast majority will have been pre-ordered.”