Gen has written to advertisers outlining proposals to scrap the existing remuneration system, which charges clients 15 per cent to 20 per cent commission, in favour of a transparent trading system.
It is understood key advertisers have held talks with their outdoor media agencies about the move and some have asked ISBA for advice.
The outdoor sector is dominated by Kinetic and Posterscope, which together control 90 per cent of the market.
According to outdoor sources, advertisers are increasingly dissatisfied with the commission system and the service they receiving from specialist agencies.
Gen's managing partner, Michael Higgins, said: "We believe the market is ready for a change. We recognise that the existing specialist model has become stagnant and predictable and fails clients looking for an advantage."
Launched in 2003, Gen is run by three former directors of Blade - Malcolm Thomas, Nick Maddison and Steve Wilson - and the ex-Mills & Allen sales and marketing director, Michael Higgins.
Last week, 20th Century Fox moved its £4 million outdoor planning and buying account from Kinetic to Gen.
- Comment, page 40.