Trade and industry secretary Alistair Darling has referred satellite operator BSkyB's purchase of a stake in ITV to the Competition Commission (CC).
The rival broadcasters have already been subject to investigations by the Office of Fair Trading (OFT) and media regulator Ofcom but Mr Darling said this morning a "fuller investigation" was required into the 17.9 stake.
Last November's purchase occurred while ITV was subject to takeover bids from cable rival NTL, which has subsequently merged into Virgin Media.
The OFT reported on April 27th that a "relevant merger situation" had been created by the acquisition. John Fingleton, its chief executive, said the link meant ITV was "no longer fully independent" and that the "high stakes" for Britain's millions of viewers meant an investigation was required.
At the same time Ofcom found there were public interest issues "to the plurality of news provision to the UK audience".
BSkyB emphasised at the time it had no intention of acquiring more than 19.9 per cent in the commercial broadcaster or a controlling interest.
Now Mr Darling has acted to investigate whether the acquisition is acceptable.
"On the basis of the evidence before me, a fuller investigation by the Competition Commission is justified," he said.