Sales of the PlayStation 3 video game console jumped in the weeks after a $100 price cut last month, and strong demand could lead to empty shelves at retail, a Sony Corp executive said on Wednesday.

We are up about 300 percent over where we were pre-price drop, Jack Tretton, chief executive of Sony Computer Entertainment of America, said in an interview. We are up significantly versus last year.

The increase represents sales in the three weeks after Sony slashed the price of the PS3 to about $300 in the United States last month, compared with sales for the three weeks before. The PS3's sales have lagged behind Nintendo Co Ltd's Wii and Microsoft Corp's Xbox.

A few days after Sony's price cut, Microsoft dropped the price of its Xbox 360 Elite to $299. Several technology blogs this week have reported that Nintendo is poised to cut the price of the Wii.

Tretton noted that higher demand for the PS3 could leave some retailers out of stock of the device, which lets users surf the Web and watch films on Blu-ray discs, in addition to playing games.

If things continue at this pace, it is conceivable that there will be product shortages, he said.

Tretton noted that Sony is on pace to meeting its goal of selling 13 million units by the end of its fiscal year in March, compared with 10.06 million units sold the previous year by the Japanese electronics and entertainment conglomerate.

Tretton said he expects the price cuts and a lineup of popular games due ahead of the Christmas holiday will lift the entire video game industry, following some six months of sales declines.

So far this year, industry sales are down 14 percent, but could finish 2009 flat to up, he says, since half of the industry's annual sales occur between September and December. In that period will come highly anticipated updates to franchises including Sony's God of War and Activision Blizzard's Call of Duty.

In a very difficult economy ... I couldn't be more optimistic about our fortunes for the rest of the year and for the future, he said.

(Reporting by Franklin Paul; Editing by Leslie Gevirtz and Richard Chang)