Sony Corp needs to establish an unwavering marketing strategy for its PlayStation 3 game machine to drive growth of its console business, the head of Japanese videogame publisher Square Enix Co Ltd said.

Sony first unveiled the PS3 as a mighty home electronics product. Then, after some badgering from game companies, it shifted the position of the console closer to a game machine, Square Enix President Yoichi Wada told reporters on Friday.

(The future of the PS3) would be tough if its marketing strategy is not straightened up, he said.

Sony's PS3 is packed with cutting-edge technologies such as a Blu-ray high-definition DVD player and a Cell microchip, dubbed supercomputer on a chip, making it advanced enough to be a hub of living room electronics, a high-speed gateway to the Internet, as well as a game machine.

But on the downside, these state-of-the-art capabilities drove up manufacturing costs. The basic version of the PS3 retails twice as high as Nintendo Co Ltd's Wii.

The high price and scarcity of strong game titles have caused the PS3 to lag far behind the Wii in unit sales since their launches late last year.

In a sign of changing fortunes of the two Japanese video game makers, Nintendo in June became one of Japan's 10 most valuable companies, and in doing so, bumped Sony off the top 10 list.

Shares in Sony, locked in a battle with Nintendo and Microsoft Corp for dominance in the $30 billion video game industry, closed down 1.4 percent at 5,640 yen, while Nintendo fell 1.5 percent to 52,900 yen.

Square Enix, known for such blockbuster game titles as Dragon Quest and Final Fantasy, was up 1.1 percent at 3,750 yen.