Commercial radio stations in London are looking for a new way to measure audience figures.
The capital's three main stations, owned by GCap, Chrysalis Group and Emap, are in talks with RAJAR (Radio Joint Audience Research) in a bid to solve fluctuations in ratings figures, which the broadcasters say are depriving them of millions of pounds in ad revenues.
The proposals under discussion are that data should be drawn from six months' of listening statistics, rather than the current three months.
The London radio market is the largest and most lucrative in the UK and Chrysalis boss, Phil Riley, believes RAJAR's measurement system is being pushed to its limits.
He says: "We're all seeing RAJAR show more volatility than it used to. We have got an increasingly sophisticated market and we need an increasingly sophisticated RAJAR system to cope with it."
The ratings body has confirmed it is "looking at ways of increasing the survey sample to reduce volatility".
It is also under increasing pressure to introduce electronic meters to replace its antiquated paper diary system [WAMN: 08-Jul-05].
Data sourced from MediaGuardian.co.uk; additional content by WARC staff