The Bush administration signalled on Thursday that it was giving up on its bid to push through controversial new rules on media ownership, after it decided not to appeal against a court ruling that blocked the new policies from being enacted.

The decision will in effect force the Federal Communications Commission, the US media regulator, to restart a lengthy evaluation of the state of US media laws, which govern how big and far-reaching such companies as News Corporation and Viacom the companies behind Fox and CBS respectively should be allowed to expand.