The Polski Operator Telewizyjny (POT) consortium has begun joint MPEG-2 and MPEG-4 DTT trials in Warsaw. Backed by the national commercial broadcasters Polsat and TVN, POT initially had a one-month licence to undertake DTT trials in Warsaw and Srem near Poznan in June. However, the Office of Electronic Communications (UKE) subsequently extended it until the end of the year. Separately, TP Emitel has stopped undertaking DTT trials in the city of Wroclaw. It is believed the frequency it has been using will be allocated to TV Puls, the regional station owned by Rupert Murdoch’ s News Corp.