Facebook and Warner Bros have announced a movie rental service that will be available for users of the social network site for $3.

Subscribers will be provided with a 48-hour window to watch the film for 30 Facebook Credits or $3.

The two companies will test the collaborative project with The Dark Knight, which already has about four million "likes" on its Facebook page.

Warner Bros president of digital distribution Thomas Gewecke said the move is a natural extension of the company’s distribution strategy.

Gewecke said, "Facebook has become a daily destination for hundreds of millions of people. Making our films available through Facebook is a natural extension of our digital distribution efforts."

Warner Bros said it will allow more movies for both rental and purchase in future. Other media companies are also expected to follow Warner Bros in renting and eventually sell movies on the social networking site.

Howver, the move is expected to hurt the market share of Netflix, an online movie rental service provider as another e-commerce player Amazon recently announced that it will provide its customers some online video for free.

At present, the service is restricted to the US and is unavailable in the UK.