BRUSSELS, April 2, 2008 (AFP) - The European Commission opened on Wednesday a state-aid investigation into subsidies for British broadcaster Channel 4's investments in digital technology amid 'serious doubts' they threaten competition.

'The commission is firmly committed to encouraging the digital switchover process, which has many advantages for consumers and innovation,' EU Competition Commissioner Neelie Kroes said in a statement.

'However, it needs to make sure that any state support does not distort competition unduly,' she added.

The European Commission is responsible for policing state aid in Europe to make sure that it does not give companies an unfair advantage and distort competition.

British authorities informed the commission in October of plans to grant 14 million pounds (18 million euros, 28 million dollars) in aid to Channel 4 to help it cover the costs of switching over to digital technology.

Even before that, the commission had received a complaint from an unnamed British rival that Channel 4 had enough funds to meet its investment needs without state aid.

'The commission has serious doubts as to whether the proposed aid to Channel 4 meets the criteria ... that the aid is necessary and proportional and does not overcompensate Channel 4,' it said.

Although Channel 4 is commercially run, it is publically owned.