He wants Extreme rolled out across Europe after its UK launch.
Karkosik, 56, ranks 557th on the Forbes billionaire rich list. He made his fortune with investments in steel, copper and chemicals. Through Centernet, a telecoms company wholly owned by Karkosik’s Midas investment fund, he is planning to launch Poland’s fifth national and first 3G mobile network.
Centernet has an 80 per cent share in Extreme and Advantage’s parent company Xebra.
Advantage group managing director John McFarnon said the company would know by October if it had been successful in securing Poland’s fifth network licence. He said Extreme would launch as an MVNO in Poland next year regardless, through incumbent network Polska Telekom.