The outgoing head of MetLife Inc., the largest U.S. life insurer, has a message for business leaders: Don’t abandon the public square.In his parting letter to shareholders, Chief Executive Officer Steven Kandarian urged fellow executives to push for policies that preserve free markets, create wealth and raise living standards.He led MetLife in suing the government over the company’s designation as a systemically important financial institution, a tag that was eventually dropped. More recently, he’s defended corporate share buybacks.“It is important for companies to take a public stand and advocate for policies that are in the best interest of their customers, employees and shareholders,” wrote Kandarian, who retires at the end of the month after eight years at the helm.Kandarian cited stances MetLife took during his tenure, which he said helped both the insurer and the country overall.“While the SIFI challenge was our most prominent example, we also made our views known on taxes, regulation, trade and monetary policy,” he wrote.“The pro-growth positions we took, many of which became official policy, have helped fuel the strongest U.S. economy in a decade -- and better results for MetLife, as well.”