Mutual of Omaha Mortgage remained the nation’s largest reverse mortgage lender in May, even as overall Home Equity Conversion Mortgage (HECM) endorsements continued to decline, according to a report released Monday by HECMWorld.com that utilizes data from Reverse Market Insight (RMI). Mutual of Omaha recorded 423 HECM endorsements during the month, upping its total to 2,169 on a year-to-date basis....