The move is an effort by Google and Intel to extend their dominance of computing to television, an arena where they have little sway. For Sony, which has struggled to retain a pricing and technological advantage in the competitive TV hardware market, the partnership is an effort to get a leg up on competitors.

The partners envision technology that will make it as easy for TV users to navigate Web applications, like the Twitter social network and the Picasa photo site, as it is to change the channel.

Some existing televisions and set-top boxes offer access to Web content, but the choice of sites is limited. Google intends to open its TV platform, which is based on its Android operating system for smartphones, to software developers. The company hopes the move will spur the same outpouring of creativity that consumers have seen in applications for cellphones.

Google is expected to deliver a toolkit to outside programmers within the next couple of months, and products based on the software could appear as soon as this summer.

The three companies have tapped Logitech, which specializes in remote controls and computer speakers, for peripheral devices, including a remote with a tiny keyboard.

The project, which has been under way for several months, was described by people with knowledge of it. They requested anonymity because the partners were not allowed to speak publicly at this point, and details remained under negotiation.

Spokesmen for Google, Intel and Logitech declined to comment. A Sony spokesman said he was not familiar with the project. The companies appear to be hiring for Android-related jobs. Intel, for example, has listed jobs for senior application engineers with Android programming experience who can help extend Intel’s technology “from PC screen to mobile screen and TV screen.” Logitech also has several job listings for Android developers, including a position for an “embedded software engineer” with experience building “audio and video products based on the Android platform.”

Jacob Hsu, chief executive of Symbio, a contract engineering firm that does work for consumer electronics companies, said there was rising interest in set-top box technology among the traditional computing players. “The boxes are just getting more and more powerful, so there’s more you can do with them,” he said.

For Google, the project is a pre-emptive move to get a foothold in the living room as more consumers start exploring ways to bring Web content to their television sets. Google wants to aggressively ensure that its services, in particular its search and advertising systems, play a central role.

“Google wants to be everywhere the Internet is so they can put ads there,” said one of the people with knowledge of the project.

Based on Google’s Android operating system, the TV technology runs on Intel’s Atom chips.

Google has built a prototype set-top box, but the technology may be incorporated directly into TVs or other devices.

The Google TV software will present users with a new interface for TVs that lets them perform Internet functions like search while also pulling down Web programming like YouTube videos or TV shows from Hulu.com. The technology will also allow downloadable Web applications, like games and social networks, to run on the devices.

A person with knowledge of the project said that Google TV would use a version of Google’s Chrome Web browser, which currently does not work on Android phones.

Google’s efforts to break into television advertising date back three years. Through a program called Google TV Ads, the company sells advertising on a handful of satellite and small cable television systems, as well as some cable networks. Google says thousands of advertisers have signed up for the program, but analysts say they believe the amount of revenue generated is too small to have a significant impact on Google’s overall business.

The partners will face a crowded field. In addition to the makers of traditional cable and satellite set-top boxes, Cisco Systems and Motorola, many others have entered the game, including Microsoft, Apple, TiVo and start-up companies like Roku and Boxee, which already stream video from Netflix, MLB.com and other Web sites directly to television sets. Yahoo is also promoting a TV platform that uses small software programs called widgets to use certain Web services.

Anthony Wood, founder and chief executive of Roku, said that a browser-based Google TV box would require an expensive chip and would probably cost $200 or more, compared with a cheaper alternative, like Roku’s $80 device. The device streams content from more than a dozen sites, including Netflix, Blip.TV and Amazon.com. Moreover, “on the TV, people want specific TV apps, not a browser experience,” he said.

For Intel, the effort represents a way to get its line of energy-efficient Atom chips, currently found in laptops, into TVs. Intel executives have talked for a couple of years about creating PC-like TVs, contending that it will take the horsepower of a mainstream chip to play high-definition movies well on bigger screens. Any success with TVs would help Intel get into a new, high-volume market and possibly offset some of the pressure the company now feels from rivals creeping up into computers.

The Google TV software will be open source at its core, meaning that device and TV makers should have broad access to it.

Sony, however, hopes to gain an edge over competitors by bringing out the first appliances and possibly TVs running the software, perhaps under a new brand. The Japanese consumer electronics giant, which owns Sony Pictures, is not expected to put its movie content directly on the devices but will probably have a link to a digital store.

A person with knowledge of the Google TV project said that the set-top box technology was advanced enough that Google had begun a limited test with Dish Network, one of Google’s partners in the TV Ads program. A spokeswoman for Dish Network declined to comment. This month, The Wall Street Journal reported that Google and Dish were testing a TV program search service.

Ashlee Vance and Miguel Helft contributed reporting.

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