The Associated Press

NEW YORK | Four major newspaper publishers are forming an online advertising sales network in the industry's latest attempt to claw back some of the ad dollars that are increasingly migrating to the Internet.

Gannett Co. and Tribune Co.., the largest and second-largest publishers in the country, are joining Hearst Corp. and The New York Times Co. to form company that will sell online ad space across a network of newspapers in many large cities including New York, Los Angeles and Chicago.

The joint venture, which launched on Friday, will be based in Chicago and operate under the name QuadrantOne. It won't include USA Today or The New York Times itself, which already have significant online ad sales operations of their own. It will include The Boston Globe, which is owned by The New York Times Co.

The network will operate separately from a consortium of newspapers that has banded together with Yahoo Inc. to sell advertising as well as cooperate in other areas including online search and help-wanted classifieds.

An earlier effort by newspaper publishers to band together on online advertising called the New Century Network ended in failure in the 1990s. Currently, an industry group called the Newspaper National Network also sells print as well as online ads across a network of newspapers.

Newspaper publishers have been struggling with declining print advertising revenues for more than a year as ad dollars increasingly go online.