Online search firm Yahoo has forged a string of deals it hopes will help put its services on the world's televisions.

The promise of “convergence” between the internet and TV is as old as the web but has so far failed to gain traction.

Yahoo, lagging behind its arch-rival Google, hopes to change that with agreements with companies including Samsung, LG Electronics, Sony and Vizio, which will make high-definition TVs that support Yahoo's online service.

The new TVs are expected to be on the market as early as the spring and will support widgets — small internet applications — that run alongside broadcast TV content.

The applications can be used for a wide array of web activities, like watching videos on Google's YouTube.com, social networking on News Corp's MySpace.com, tracking stocks and sports teams, buying and selling on eBay, messaging friends using Twitter, or using Yahoo's own photo-sharing website Flickr.

Patrick Barry, vice president of connected TV at Yahoo, says the aim is to generate more advertising revenue as television “is still top of mind for advertisers”.