Fannie Mae this week tapped its chief administrative officer and general counsel to replace the company’s outgoing chief executive even as a bipartisan group of senators say they “remain deeply concerned” about “excessive” executive compensation at both government-sponsored enterprises. Fannie’s board of directors announced, with the Federal Housing Finance Agency’s consent, the appointment of Timothy Mayopoulos as president and CEO and elected him a member of the board. Mayopoulos, 53, currently holds the title of executive vice president but has managed several critical functions since he joined Fannie...