Merger talks between Channel 4 and Five have been called off because of the complexity of combining the public and commercial stations.
Andy Duncan took over as chief executive of Channel 4
Channel 4 said it did not believe the proposed merger would be of any benefit to them.
Five admitted there would have been benefits if it had gone ahead but there would have been too many constraints.
Merger talks began earlier in the year as Granada and Carlton were merging under the ITV umbrella.
It was thought Channel 4 and Five may fare better in the increasingly competitive UK commercial sector if they worked more closely together.
Protect and strengthen
Discussions were started under the former chief executive Mark Thompson, who has since left to become director general of the BBC.
He was replaced by Andy Duncan who had been the director of marketing at the BBC.
Mr Duncan said: "With concerns being raised about our future funding it was legitimate for Channel 4 to explore this merger, but we've concluded that protecting and strengthening Channel 4's public service role isn't compatible with the full merger that was proposed."
A Five spokesman said that although the benefits of a merger would have been "siginificant", their shareholders concluded that "the complexity of combining a commercial and a publicly owned entity, and the constraints on the likely structure, would have been too great".