Preliminary combined net income for the 12 Federal Home Loan Banks fell 12.3 percent to $580 million in the first quarter of 2013, down from $661 million at the end of the fourth quarter and a 20.9 percent decrease from the same period last year, according to the Federal Home Loan Bank Office of Finance. The FHLBank systems’ $153 million year-over-year decrease was driven primarily by lower net interest income, partially offset by lower assessments and non-interest expense. Total FHLBank assets were $738.7 billion on March 31, 2013, down 3.1 percent from $762.5 billion on Dec. 31, 2012, due to declines in investments, advances, mortgage loans and other assets.