Fannie Mae and Freddie Mac mortgage-backed securities remained the preferred investment choice of the 12 Federal Home Loan Banks during the third quarter of 2012, with a slight decrease from the previous quarter, according to a new analysis and ranking by Inside The GSEs based on data from the Federal Housing Finance Agency. Meanwhile, Ginnie Mae securities posted a modest increase within the FHLBank system during the period ending Sept. 30, 2012.