The two sibling GSEs experienced a divergent earnings period during the fourth quarter of 2011, as Freddie Mac posted a quarterly gain, on paper anyway, while Fannie Mae announced losses, albeit at a slower pace, in a year that drove both companies even deeper into the red.Freddie posted net income of $619 million during the three month period ending Dec. 31, 2011, compared to a net loss of $4.4 billion during the third quarter. For the full year, the company reported a net loss of $5.3 billion, compared to a net loss of $14.0 billion for the full-year 2010.