Reyes switched to chief risk officer from chief investment officer in July, shortly before unusually high claims pushed the company’s general insurance unit to a third-quarter loss of $183 million and prompted it to drop a bid for Britain’s RSA Insurance Group Plc. Zurich is bringing back Mario Greco, who oversaw general insurance before he left in 2012, this time as chief executive officer starting in May to replace Martin Senn who stepped down in December