Some of the country's largest Internet service providers are poised to leap into the antipiracy fight in a significant way.

After years of negotiations, a group of bandwidth providers that includes AT&T, Comcast, and Verizon are closer than ever to striking a deal with media and entertainment companies that would call for them to establish new and tougher punishments for customers who refuse to stop using their networks to pirate films, music and other intellectual property, multiple sources told CNET.

The sources cautioned that a final agreement has yet to be signed and that the partnership could still unravel but added that at this point a deal is within reach and is on track to be unveiled sometime next month.

This has been in the works a long time. The Recording Industry Association of America (RIAA) and Motion Picture Association of America (MPAA), the respective trade groups for the four major record companies and six top Hollywood film studios, have labored for years to persuade ISPs to take a tougher antipiracy position. Under the proposed plan, participating bandwidth providers would adopt a "graduated response" to subscribers who repeatedly infringe copyrights. ISPs would first issue written warnings, called Copyright Alerts, to customers accused by copyright owners of downloading materials illegally via peer-to-peer sites, the sources said. Should a subscriber fail to heed the warning, an ISP could choose to send numerous follow-up notices. Eventually, the plan requires ISPs to take more serious action.

Participating ISPs are given plenty of leeway to choose how to proceed. They can select from a "menu" of responses outlined in the plan, such as throttling down an accused customer's bandwidth speed or limit their access to the Web. For example, a suspected pirate may be allowed to visit only the top 200 Web sites until they stop illegal file sharing. The subscriber may also be asked to participate in a program that educates them on copyright law and the rights of content creators. The ISPs and copyright owners will share the costs of operating the program, sources said.

At least on paper, the proposal appears to have the potential to become one of the most potent antipiracy strategies ever implemented. The ISPs involved provide Internet access to a large percentage of the U.S. population and because they are among the Internet's gatekeepers, the network providers are in a unique position to act as copyright enforcers. Critics have argued that a graduated response doesn't allow for due process. They reject the notion that an ISP should limit a person's service based solely on accusations made by copyright owners.

White House helps shepherd deal But enlisting the assistance of some of the top ISPs represents a major victory for the film and music industries. Certainly, they had plenty of help. For starters, the National Cable and Telecommunications Industry has been involved in brokering the deal, the sources said. Some of the NCTA's members include Time Warner Cable, CableVision, Charter Communications, Comcast, and Qwest Communications, but not all the group's members are participating, according to the sources.

Spokespeople for the NCTA, RIAA, and MPAA declined to comment. Representatives from some of the known participating ISPs, such as AT&T and Comcast, couldn't immediately be reached for comment.

In addition to the NCTA, the White House was also instrumental in encouraging the parties to reach an agreement, the sources confirmed. President Obama has vowed to step up the fight against piracy and counterfeiting, and his administration has lobbied Congress the past several years to pass new pro-copyright legislation while instructing federal law enforcement to make antipiracy a priority.

It's tough to deny that most of the momentum in the online copyright wars appears to be with content creators. In the past year, a federal court ruled that the top music file-sharing service LimeWire induced copyright infringed and ordered the network be shut down. In recent months, the U.S. Immigrations and Customs Enforcement (ICE) agency has seized domain names from dozens of sites accused of trafficking in pirated content or counterfeit goods. In the U.S. Senate, lawmakers are expected to pass legislation that would enable the government to block U.S. Internet users from accessing alleged pirates sites based overseas.

When it comes to the proposed agreement on graduated response, the term was sometimes referred to also as a three-strikes plan. The sources who spoke to CNET said this isn't an accurate description of what the latest plan calls for, as an ISP gets to choose how many times to notify a customer before interrupting service. In the past, a three-strikes strategy also was supposed to lead to a complete termination of service for chronic file sharers. Kicking someone off a network for good is not required under the proposed agreement, the sources said.

If the term graduated response sounds familiar it's likely because of the RIAA. The trade group claimed in December 2008 that several ISPs, which were never identified, had agreed to adopt graduated-response programs to help the top record labels fight illegal file sharing. Up to that point, the RIAA's antipiracy strategy was built around filing lawsuits against individual users. After the RIAA abandoned the litigation campaign against individual users it did see several ISPs begin booting small numbers of people off their networks. In the years since, however, no major bandwidth provider openly acknowledged adopting a graduated response.

Sources in the music and film sectors said that their antipiracy measures, coupled with the emergence of popular legal services, such as Netflix and Amazon, which provide inexpensive content that is also easy to access, has put them in the best possible position to compete with Web piracy.