Five large U.S. broadband providers will warn subscribers of illegal file sharing detected on their accounts under a new agreement with members of the entertainment industry, the groups announced Thursday.

The warnings of illegal file sharing will not result in broadband subscribers having their accounts closed, but after several warnings, they may be directed to a landing page online and be forced to contact their ISPs before being able to surf the Web, officials said. Broadband providers may use other "mitigation" efforts.

Other mitigation efforts could include a temporary reduction of broadband speeds, or a requirement that the broadband subscriber review copyright educational materials, participants said. In most cases, a mitigation effort would be required after five notices to a subscriber, said Cary Sherman, president of Recording Industry Association of America (RIAA).

The agreement, however, is not a "three strikes and you're out" system of terminating service, as rumored for several weeks, said Thomas Dailey, vice president and deputy general counsel at Verizon Communications. ISPs will not filter Web traffic under the agreement, but they will attempt to educate consumers about the risks of illegal file sharing, he said.

ISPs will not share subscriber names with the entertainment industry, Dailey said. Broadband subscribers will be able to challenge the notices, he said.

The "vast majority" of broadband subscribers will never receive a notice because they aren't engaged in illegal file trading, said James Assey, executive vice president of the National Cable and Telecommunications Association (NCTA), a trade group representing cable broadband providers.

Many broadband subscribers don't understand copyright infringement law, and the educational efforts in the agreement are important, Assey added. "As a general matter, we give our subscribers the benefit of the doubt," he said. "But we also want to help them better understand what's fair and what's not, and also to understand that to continue to engage in content theft does have consequences."

Some ISPs already forward notices of copyright infringement generated by entertainment trade groups. But the new agreement creates a standard notification effort and includes a consumer education component, participants said. "This is a landmark agreement," Sherman said.

Other broadband providers participating in the agreement include AT&T, Comcast, Cablevision Systems, and Time Warner Cable. In addition to the RIAA and its members, members of the Motion Picture Association of America, the American Association of Independent Music, and the Independent Film and Television Alliance will participate in the agreement.

The RIAA retains the right to file lawsuit against large file sharers, Sherman said.

Grant Gross covers technology and telecom policy in the U.S. government for The IDG News Service. Follow Grant on Twitter at GrantGross. Grant's e-mail address is grant_gross@idg.com.