LOS ANGELES – A coalition of major media and Internet companies Thursday issued a set of guidelines for handling copyright-protected videos on large user-generated sites such as MySpace.

Conspicuously absent was Google Inc., whose YouTube Web site this week rolled out its own technology to filter copyrighted videos once they’ve been posted.

Media companies Walt Disney Co., Viacom Inc., CBS Corp., NBC Universal and News Corp. joined Internet companies Microsoft Corp., MySpace, Veoh Networks and Dailymotion to issue the guidelines, which would require sites to use filtering technology to block copyrighted clips from being posted without permission.

The incentive for the coalition’s Web sites and others to comply is the media companies’ promise not to sue if any copyrighted material sneaks past their best efforts to block it.

“Today’s announcement marks a significant step in transforming the Internet from a Wild West to a popular medium that respects the rule of law,” NBC Universal president and chief executive Jeff Zucker said in a statement. “By recognizing the mutual benefits of a technology-based framework to control piracy, technology and content companies have laid the foundation for the lawful growth of video on the Internet.”

Web companies that are being sued by content owners might be reluctant to join such coalitions, especially when other coalition members are seeking compensation for past violations, said Internet attorney Andrew Bridges of the San Francisco firm Winston & Strawn.

“In general, it’s not a surprise that companies in litigation can be reluctant to join something that may be only a partial resolution to an overall dispute,” Bridges said.

Bridges called Thursday’s guidelines more of a treaty than a contract, noting that the coalition members specifically stated that the guidelines do not preclude any company from seeking legal remedies in a dispute.

“These principles may be a noteworthy attempt to reach some common ground that could minimize friction and minimizing friction is good for everybody except the lawyers,” Bridges said.

The guidelines, which do not apply to search engines, e-mail or browsers, are designed for sites that host user-generated clips – like YouTube.

YouTube, which is being sued by Viacom for allowing copyrighted videos to be posted on its site, announced its long-awaited filtering technology Monday.

That technology would identify unauthorized content after it is posted on the site, then take steps to remove it.

In contrast, Thursday’s guidelines require that sites use technology to block offending clips before they are posted online.

The guidelines also require Web sites to identify Web sites that repeatedly try to upload unauthorized content and either block those sites or remove links to them.

Media representatives who asked not to be quoted said that Google had initially participated in discussions, but later decided not to participate in the coalition.

YouTube issued a statement Thursday that reopened the door for cooperation.

“We appreciate ideas from the various media companies on effective content identification technologies,” Jeremy Doig, YouTube director of engineering, said. “We’re glad that they recognize the need to cooperate on these issues, and we’ll keep working with them to refine our industry-leading tools.”

Viacom chief executive Philippe Dauman said Thursday he was surprised when Google’s announcement of new filtering technology came out just days before the coalition announced its guidelines.

“They knew about this announcement today,” Dauman said at a Web conference in San Francisco

For his part, Dauman said he kept a “completely open mind” when he met one year ago with Google CEO Eric Schmidt.

“They talked then about having a filtering system,” Dauman said. “They can do things very quickly when they want to…. I guess they haven’t wanted to.”

Despite Viacom’s pending $1 billion lawsuit against Google, Dauman predicted that “at some point in the future we’ll work with Google.”

The new guidelines require Internet companies to have in place by the end of 2007 filtering software that blocks all content media companies flag as being unauthorized.

The guidelines also require that user-generated video sites also keep their filtering technology up to date, and they call for cooperation between media and Web companies to allow “wholly original” user-generated videos to be posted and to accommodate “fair use” of copyrighted material as allowed under law.

The guidelines do not specify how liberally or conservatively the term “fair use” will be defined. Fair use provisions of the U.S. copyright act allow segments of copyrighted works to be used for purposes of parody or satire or in reviews and other limited circumstances.

AP Business Writer Rachel Konrad contributed to this article from San Francisco