Sony’s video game unit said yesterday that Ken Kutaragi, the father of the PlayStation game console, would no longer run its day-to-day affairs. The move comes just weeks after Mr. Kutaragi’s latest creation, the PlayStation 3, hit the market following a year of delays and technical problems.

Mr. Kutaragi, who is a celebrity among consumers in Japan and has had a sometimes stormy relationship with his superiors at Sony, will remain chief executive of Sony Computer Entertainment. He will also become chairman but will give up control of daily operations. Starting today, that job will belong to Kazuo Hirai, who has been running the game unit’s American division.

Mr. Hirai will have his hands full. Introduced last month, well behind schedule, the PlayStation 3 is now in a pitched battle with a new game console from Nintendo and the Xbox 360, made by Microsoft, which has closed the gap with Sony in the roughly $30 billion global game market.

It is too early to say whether Sony, Microsoft or Nintendo, which began selling the Wii last month, will win the fight for consumers’ imaginations and money. But some industry analysts said the timing of Sony’s management shake-up, so soon after the machine’s release, suggested a company unhappy with the slow start for its marquee product.

“There was a significant increase in the market share for Xbox because of the delay, and the PS3’s higher price will also have an impact,” said Todd Dagres, a partner at Spark Capital, a $260 million venture capital firm focused on entertainment and technology. “You have to look at it and say Sony didn’t do themselves any favors, and usually they try to place the blame somewhere.”

Sony said the management shuffle would strengthen oversight of its video game operations, which it sees as critical to its recovery. The company has faced a series of problems lately, from expensive laptop battery recalls to sinking profits and a failure to win back the portable music market from Apple’s iPod.

Mr. Kutaragi will be responsible for strategic thinking at the game unit, Sony said, while Mr. Hirai will handle shorter-term issues.

For Sony, the importance of the PlayStation 3 extends beyond its battle against Microsoft. The consoles have come to symbolize a transition in the world of consumer electronics to a digital, Internet-centered world, one in which Microsoft has a strong position, and away from the stand-alone consumer electronics that made Sony into a giant.

Sony is marketing the PlayStation 3 not just as the future of gaming, but also as a digital entertainment system that plays high-definition movies and serves as a hub in the living room, connecting the Internet, stereo and television. And its fate is being seen as a test of the ability of Howard Stringer, Sony’s chairman, to revitalize the company.

Much depends on whether Sony can get enough consoles into consumers’ hands. While the company says it expects to ship one million machines in North America by the end of the year, it may end up shipping only half that amount at best because of component shortages, according to Evan Wilson, an entertainment analyst at Pacific Crest Securities.

Inside Sony, Mr. Kutaragi has had a reputation as an inspired but volatile leader. In the early 1990s, he threatened to leave the company when he had trouble persuading Sony to get into the game console business.

At Japanese companies, where executives are less likely to be publicly blamed for problems than in the West, a promotion combined with removal from day-to-day control over a product or group can sometimes be a way to penalize an executive.

But some analysts said the move would give Mr. Kutaragi more time to focus on Sony’s broader strategy — and possibly prepare to succeed Mr. Stringer.

The management change is “either a Machiavellian scheme to get rid of Kutaragi or they’re grooming him to replace Sir Howard,” said Michael Pachter, a video game industry analyst with Wedbush Morgan Securities. “I think it’s the latter.”

Whatever Mr. Kutaragi’s role as chief executive, the promotion of Mr. Hirai may signal that Sony needs fresh energy to help it smooth out the manufacturing and distribution of its new console.

“They need as much management talent at Sony headquarters as possible,” Mr. Wilson said.

Mr. Hirai, 45, has been a vocal and enthusiastic cheerleader for the PlayStation 3. He joined the American game unit in 1995 and became its president in 1999.

He has not overseen manufacturing before, but because of his experience distributing the consoles in the United States, he understands what it takes to build the product, said David Karraker, a spokesman for Sony Computer Entertainment of America.

“He has an intricate knowledge of what goes into the products, and how to get them into the various territories,” Mr. Karraker said. He said Mr. Hirai was not available to comment on his new appointment.

Jack Tretton, the executive vice president and chief operating officer of the American unit, will move into Mr. Hirai’s current role.

The PlayStation 3 thus far has left industry analysts and eager consumers wanting. A big reason for the slow release of the machine was that Sony was still developing the Blu-ray high-definition DVD player that is an important part of it, Mr. Wilson said.

As a result of that and other complex components, the PlayStation 3 is selling for as much as $600, about $200 more than the comparable version of the Xbox 360. At the same time, Microsoft has moved faster into the world of online gaming, getting a head start on a growing trend. This has helped the Xbox 360 overcome some of its technical shortcomings compared with the PlayStation 3, which some consider a more sophisticated machine.

“It’s been a very, very difficult launch,” said Mike Hickey, a video game industry analyst at Janco Partners, who characterized the management changes as “a heavy move,” particularly Mr. Kutaragi’s new job.