By Lefteris Papadimas ATHENS (Reuters) - Greek President Prokopis Pavlopoulos is expected on Friday to call a snap election for next month, an official at the presidency told Reuters, ending fruitless coalition efforts among parties deeply divided over the country's new bailout. Following last week's resignation of leftist Prime Minister Alexis Tsipras, Pavlopoulos asked a conservative and a radical left leader to try to form a new government and thereby avoid another election just seven months after the previous poll. The official stressed on Wednesday that the timetable could still change, but said Pavlopoulos intended to appoint a caretaker premier, Supreme Court judge Vassiliki Thanou, on Friday.