The Fed may concentrate first on trimming purchases of Treasuries, while continuing to buy mortgage bonds to keep a lid on interest rates for home loans, according to Bloomberg.

"There is a valid case to slow down Treasury purchases before MBS purchases," said Roberto Perli, a partner at Cornerstone Macro LP in Washington and a former economist for the Fed’s division of monetary affairs. "The recent sharp increase in mortgage rates poses a threat to the housing recovery, and a continued housing recovery is necessary if the economy is to stay on a more robust trajectory."

Policy makers led by Fed Chairman Ben S. Bernanke have said in the last two months that the central bank’s mortgage-backed securities program has helped the economy, with Boston Fed President Eric Rosengren urging reduction first in Treasury buying and San Francisco Fed’s John Williamssaying mortgage buying was "more powerful."