Product placement is a regular feature of Hollywood films

Product placement has been a feature of films such as James Bond for years, but has been banned under TV rules.

"No-one watches a Bond movie and, unless they are very rich, rushes out to buy the latest Aston Martin," Ofcom chief executive Stephen Carter said.

"So, in principle, why not in television?," he added.

Mr Carter said he could approve new ways of raising money from advertising in response to hi-tech threats to commercial channels.

'Cadillac Channel'

In theory, product placement - where real products are given prominence for a price - could be allowed in dramas, comedies and other entertainment shows but not news and documentaries, he said.

"In practice, it is a bit harder because the genres blur more on television than they do in cinema," he said. "Clearly, we need to have a discussion about how this might develop."

He also raised the prospect of allowing advertisers to run their own channels.

"A Cadillac Channel funding Top Gear could be problematic," he said. "But a Cadillac Channel per se is less so."

'Rosy' future

He said Ofcom's "temperamental inclination" would be to allow changes if they passed two tests.

Any new ways of making money must be weighed up against the public interest, the need for editorial independence and whether viewers knew they were watching advertising, he said.

The short-term future for commercial TV was "fairly rosy", he said, adding that advertising revenues were on the up.