Television stations owned by CBS Corp announced Monday the launch of the CBS Local Ad Network, a revenue-sharing ad network that targets social media Web sites and blogs on a local basis.

The first-of-its-kind Web network will involve CBS-owned TV stations generating online modules called widgets which are added to Web sites and then updated throughout the day.

The content is delivered in real time and updated accordingly. A banner ad is contained in the widget. The online partners will receive a share of the revenue, but specific financial details were not disclosed.

The CBS Local Ad Network again positions our stations at the forefront of an unprecedented locally focused venture, said Jonathan Leess, president and general manager of the CBS Television Stations Digital Media Group.

The CBS Local Ad Network also opens up exciting new avenues for our advertising partners to efficiently extend their reach to valued local audiences while associating themselves with our CBS brands and content.

The initiative has begun to roll out in several cities, including Boston, Chicago, Dallas, Denver and San Francisco. Others that will join over the next several weeks including New York, Los Angeles, Miami, Minneapolis-St. Paul, Baltimore and Philadelphia.

The New York Times Co., The Washington Post Co. and Gannett Co.'s USA Today have all launched widgets that can be added to Web pages or personal profiles on social networking sites like Facebook.

Advertisers that have entered into the partnership agreement include AT&T, North Texas Honda Dealers and Liberty Mutual Insurance. The affiliate stations involved in these deals are cbs2chicago.com, cbs2.com and kcal9.com, cbs11tv.com and wbztv.com.