After years of suing thousands of people for allegedly stealing music via the Internet, the recording industry is set to drop its legal assault as it searches for more effective ways to combat online music piracy.

The decision represents an abrupt shift of strategy for the industry, which has opened legal proceedings against about 35,000 people since 2003. Critics say the legal offensive ultimately did little to stem the tide of illegally downloaded music. And it created a public-relations disaster for the industry, whose lawsuits targeted, among others, several single mothers, a dead person and a 13-year-old girl.

Instead, the Recording Industry Association of America said it plans to try an approach that relies on the cooperation of Internet-service providers. The trade group said it has hashed out preliminary agreements with major ISPs under which it will send an email to the provider when it finds a provider's customers making music available online for others to take.

Depending on the agreement, the ISP will either forward the note to customers, or alert customers that they appear to be uploading music illegally, and ask them to stop. If the customers continue the file-sharing, they will get one or two more emails, perhaps accompanied by slower service from the provider. Finally, the ISP may cut off their access altogether.

The RIAA said it has agreements in principle with some ISPs, but declined to say which ones. But ISPs, which are increasingly cutting content deals of their own with entertainment companies, may have more incentive to work with the music labels now than in previous years.