The radio industry was all hot and bothered yesterday on fresh rumours that the market's new dynamic duo, Richard Branson's Virgin and John Singleton's Macquarie Radio, had made an offer to Austereo for its Triple M network.

The new team on the block have made it clear they are determined to build a national FM network and showed they have money behind them when they bid $105 million unsuccessfully for a new commercial FM licence in Sydney last month.

With earnings before interest and tax estimated at about $10 million, a straight bid for Triple M could cost Virgin about $200 million but it would be difficult to split the infrastructure shared with Austereo's stronger-rating network, Today. Networks also attract more advertising when teamed together.

Some kind of joint venture is possible, with costs and revenues shared between Virgin and Austereo, and Triple M relaunched under the Virgin brand. DMG Radio and Australian Radio Network have joint ventures in Brisbane and Perth. But Austereo would be likely to demand a high price for such an arrangement.

Austereo's majority owner, film group Village Roadshow, is desperate for cash to buy back more of its troublesome preference shares and wants to commit more funds to film production. Although its executives say they want to maintain a majority stake, analysts say they aren't in radio for the long haul and might well consider a generous offer for their 60 per cent stake. Including a share of the debt, that could cost $500 million.

Macquarie will be running the numbers over any deal that makes sense, whether it be with Austereo, DMG, RG Capital Radio, or even its old sparring mate, AM broadcaster Southern Cross Broadcasting. It was keeping mum yesterday while Austereo chief executive Michael Anderson said he'd had no offers and wasn't interested in selling