The deal will see GES renamed as TV Prima Holdings. Martin Dvorak will remain as its chief executive, but MTG will choose three of the six board members.
Prima TV is the Czech Republic's second-largest commercial TV channel with a 22 per cent share of the market.
In 2008, the state-owned channels CT1 and CT2 will be forced to stop selling advertising, freeing up a further 12 per cent of the market for commercial stations.