Whether or not the plan becomes reality depends on the outcome of talks between the agencies and media owners about next year's terms and conditions.
Meanwhile, TV Nova, the country's leading channel, has said it will increase its ad rates by an average of 20 per cent next year.
The country's two other national broadcasters, Prima TV and the publicly owned Ceske televize, plan ad rate rises of 20 per cent and 15 per cent respectively.