Vodafone Group PLC (VOD.LN), the world's largest mobile operator by sales, Monday it had signed a deal with Warner Music Group Corp. (WMG) to offer music free of anti-piracy restrictions to its customers.

Warner Music's artists, which include Madonna, REM and the Arctic Monkeys, will be available in digital rights management, or DRM-free format, effectively immediately.

The Warner Music catalogue will be available to Vodafone customers in Germany, Greece, Ireland, Italy, Netherlands, Portugal, Romania, Spain and U.K., as well as partner markets in Austria, Belgium, Bulgaria, Croatia, Cyprus, Slovenia and Switzerland, Vodafone said.

The two parties will also work together to offer a range of mobile music products such as value-added album bundles that contain additional multimedia content.

In March, Vodafone secured DRM-free mobile distribution deals with the other major music labels, Vivendi SA's (VIV.FR) Universal Music Group, Sony Corp's (SNE) Sony Music Entertainment and EMI Group Ltd.

Company Web site: www.vodafone.com

-By Lilly Vitorovich, Dow Jones Newswires; 44-0-207 842 9290; lilly.vitorovich@dowjones.com