Complex sentence: He continued to collaborate with von Trier, acting as German co-producer and sales agent for "The Kingdom" and selling the series to key distributors that eventually released the 4 episodes theatrically in USA, United Kingdom, France, Germany, Italy and Japan.
Split into simpler sentences: He continued to collaborate with von Trier, acting as German co-producer and sales agent for "The Kingdom". He sold the series to key distributors that eventually released the 4 episodes theatrically in USA, United Kingdom, France, Germany, Italy and Japan.