Sony and BMG have been given two weeks to respond to European Commission objections about their plans for a merger.
The objections remain confidential, says the BBC, but many fear the consolidation would rival Universal, which currently heads the industry.
Sony and BMG need to respond to paper within two weeks. The companies can also call for a closed-door hearing. The European Commission's final decision is due on July 22.
The firms say they could save $300 million a year by consolidating. Amalgamated, their combined market share would be 25.3 per cent – Universal has 25.9 per cent.