Microsoft said yesterday that it would develop a news video distribution network for The Associated Press and share in advertising revenue generated by the newspapers and broadcasters that use it.

The A.P. Online Video Network will be available to the news service's 3,500 United States newspaper and broadcast members at no charge in the first quarter of next year, the companies said.

The agreement builds on the MSN Video service, which Microsoft started in January 2004. That service, which offers video from TV networks including NBC, Showtime and the Discovery Channel, has had a 400 percent rise in revenue.

The A.P., a nonprofit cooperative based in New York, will initially provide about 50 video clips a day covering national, international, entertainment, technology and business news. The A.P. said it would retain full editorial control over the content.

The MSN unit of Microsoft will provide the software-based video player, the technical support and the network capacity for the service. MSN will also sell the advertising and develop other network products, including local advertising and content syndication systems.