Complex sentence: He served as a senior producer at BBC World in London for over 11 years and produced and directed many documentaries and programs for leading international TV networks including BBC, German TV channel, ARD, ZDF, Sky News and other independent media houses.
Split into simpler sentences: He served as a senior producer at BBC World in London for over 11 years of his collaboration with the channel. He has produced and directed many documentaries and programs for media organisations including the BBC, German TV channel, ARD and other independent media houses.