Complex sentence: Since 2011 Michal Krupinski joins as head of department Global Banking and Markets at Bank of America Merrill Lynch for Poland, he was be based in Warsaw and be responsible for coordinating GBAM's activities in the Polish market.
Split into simpler sentences: Since 2011 Michal Krupinski joins as head of department Global Banking and Markets at Bank of America Merrill Lynch for Poland. A Polish national, he will be based in Warsaw and be responsible for coordinating GBAM's activities in the Polish market.