NBC Universal, with a TV network and movie studio, and Rupert Murdoch’s News Corp., owner of the MySpace Web site and Fox television, are seeking to reclaim the users who watch clips of their shows on YouTube, and who create their own videos. The media companies are up against a site that attracted more than 130 million visitors in January, mainly because of the user- generated clips.

“We’ll have access to just about the entire U.S. Internet audience at launch. And for the first time, consumers will get what they want—professionally produced video delivered on the sites where they live,” he added.

Traditional media companies have been rumored for months to be planning some type of joint online video service to reach a new generation of viewers who are as likely to be found in front of computers as television screens.

NBC and News Corp. were said to have tried to woo Viacom Inc. into the venture.

In a frontal assault on rival Google Inc. and its wildly popular online video division, YouTube Inc., entertainment company NBC Universal and media company News Corp. today announced plans to launch an online video Web site that will offer premium video content from more than a dozen TV networks and two major film studios.

The deal allows the two companies to join forces with a formidable list of online partners such as AOL, MSN, MySpace.com and Yahoo Inc. and includes large corporations that are already signing on as advertisers in the new venture.

The venture is aimed at giving broadcasting companies like NBC and News Corp., which owns the Fox broadcast network and the Twentieth Century Fox movie and TV studio, greater control over how their shows are distributed on the Internet. NBC, a unit of General Electric Co., also owns the Universal film studio and several cable channels including Bravo.

Rather than create one online destination, the shows will be available through a number of Web sites that already receive large amounts of visitors, including Yahoo, Time Warner Inc.’s AOL, Microsoft Corp.’s MSN, and MySpace, which is owned by News Corp.

YouTube allows for millions of users to see clips from network shows uploaded by users, but several media companies have fought what they say is unauthorized use of their programming and have demanded that it be taken down. NBC famously asked YouTube to remove unauthorized clips of mock-rap videos from “Saturday Night Live” such as “Lazy Sunday,” which had received huge numbers of viewings.

In its lawsuit, Viacom _ the parent company of Comedy Central and other traditional cable TV channels _ says YouTube is encouraging copyright infringement.

YouTube says it’s protected by law so long as it promptly takes down any copyright-protected material as soon as it’s asked to.

AOL also played down the brewing rivalry with YouTube, saying that YouTube owner Google also holds a five percent stake in AOL. So both companies will benefit as AOL draws a portion of the advertising revenue generated by the new site, Bentley said.

Likewise, MSN parent Microsoft said the new site could create a major new revenue stream through advertising dollars.

“Our investments in MSN Video and SoapBox over the past couple of years have shown us that video is an amazing driver of user engagement and excitement, both for consumers and for advertisers,” said Kevin Johnson, president of Microsoft’s platform and services division, in a release.