The US government made its latest effort to support the stricken housing market on Monday with a plan to give regional home loan banks authority to boost their holdings of mortgage-backed securities temporarily by more than $100bn. The Federal Home Loan Banks were given permission to increase for two years their purchases of MBS guaranteed by Fannie Mae and Freddie Mac, the home lenders. The decision by the federal housing finance board, the banks’ regulator, came as policymakers sought ways to support the mortgage-linked securities market.