Fannie Mae and Freddie Mac continued to trim their retained holdings of MBS and unsecuritized mortgages during the third quarter, but at a slower pace than in previous periods, according to an analysis by Inside MBS & ABS of earnings reports released this week by the two government-sponsored enterprises. One of the conditions of the conservatorships the GSEs entered four years ago was that they would reduce their retained mortgage portfolios by 10 percent a year. Those terms were revised in August to include a 15 percent annual wind-down, which would take each GSEs investment portfolio down to $250 billion by the beginning of 2018, four years sooner than under the previous arrangement. As Freddie noted...[Includes one data chart]