The Skype service on a TV will work much as it does on a PC, but with some limitations. A TV program will stop playing once a Skype call is made or answered; TV processors are not yet powerful enough to allow people to chat while they watch a show, the companies say.

Panasonic, based in Japan, and LG, based in South Korea, will sell specially designed Web cameras for their Skype-enabled sets, which should cost $100 to $200. These cameras, unlike typical webcams, are customized for the technically challenging environment of the living room, where there can be a wide range of distances between the TV and viewers.

The deals give the newly independent Skype, formerly a division of eBay, another valuable foothold in the home. About 520 million people around the world use the service to place free phone calls and have video chats with one another from their computers and other devices that run Skype software. The company makes money by charging competitive rates for people to call regular phone numbers and for add-on services like voice mail.

Video chatting has become an increasingly important feature of Skype. The company says video chats account for 34 percent of calls on the service, and as many as half on days like Christmas and New Year’s, when families seek to connect face to face.

To further nurture this activity, Skype is also announcing on Tuesday that its software for Windows PCs and televisions will support high-definition video calling in the 720p HD format, if users have webcams that support the technology.

Skype makes no money from video chats, at least for now. But Mr. Rosenberg of the company says that it may soon start charging for add-on services, like the ability to set up a video conference call for three or more parties.

“What we finally created with the Skype network is a community of users that are available via video. Having Skype on the TV is a big part of building that,” he said.