PARIS — The European Commission plans to introduce legislation on Wednesday to bolster the digital music market in Europe by streamlining the methods of agencies that collect royalties on behalf of copyright holders.

Michel Barnier, the internal market commissioner, is expected to propose a bill aimed at resolving problems at the 250 collecting societies that operate in the European Union, some of which are holding back growth in digital music. The move follows the disclosure that some of these groups have lost money on risky investments or, in some cases, failed to pay royalties owed to rights holders.

“Collecting societies need to modernize their operations to meet the challenges of a fast-evolving digital economy,” the commission says in a memo explaining the proposals. “An underlying problem is the insufficient transparency and control of the way collecting societies are managed.”

It is not the first time that the commission has taken aim at the collecting societies, which gather about €6 billion, or $7.5 billion, annually from radio stations, restaurants, bars and other music users, and distribute the proceeds to authors, composers and other rights holders. In 2008, lawmakers enacted legislation aimed at breaking down national barriers in the digital music business, making it possible for rights holders to issue pan-European licenses.