The Federal Home Loan Bank of Boston’s net income shot up almost 50 percent last year compared to 2010, according to the FHLB’s latest quarterly report.

The institution reported $64.7 million in net income in the fourth quarter, bringing its 2011 total to $159.6 million, an increase of $53 million over 2010.

Based on the returns, the bank’s board authorized a dividend of 0.49 percent, to be paid March 2. They also announced a $250 million stock repurchase plan, the bank’s first since a moratorium was established in December 2008. The bank said it plans only one such repurchase for 2012.

The strong preliminary results also prompted the bank to allocate $16.1 million to fund its 2012 Affordable Housing Program.

"In 2009, we set a course to strengthen our balance sheet, [and] preserve capital," said President and Chief Executive Officer Edward Hjerpe. "After nine consecutive profitable quarters and five consecutive quarters of dividend declarations, and retained earnings growth to nearly $400 million, we believe we are positioned to begin repurchasing excess shares from shareholders at a modest pace."

Losses on private-label mortgage-backed securities fell to $3.5 million in the fourth quarter of 2011, compared to $25.6 million in the fourth quarter of 2010.

Year-over-year net interest income was also up in the fourth quarter, rising to $81.4 million from $73.7 million for the fourth quarter of 2010. The bump was attributed to a reduction in set-asides for mortgage losses and improved margins. Net interest margins rose 13 basis points to 0.65 percent from 0.52 percent in the fourth quarter of 2010.

Total assets fell14.8 percent to $50 billion at the end of last year, down from $58.6 billion at year-end 2010. Investments decreased by $5.8 billion, advances declined by $2.8 billion, and mortgage loans dropped by $136.7 million. The reduction in advances was primarily attributable to continued high deposit levels at member financial institutions, the bank reported.