The Federal Reserve bought $7.648 billion of agency mortgage-backed securities in the week from July 31 to Aug 6, more than the $7.205 billion purchased the previous week, the New York Federal Reserve Bank said on Thursday.

In a move to help the housing market begun in October 2011, the U.S. central bank has been using funds from principal payments on the agency debt and agency mortgage-backed securities, or MBS, it holds to reinvest in agency MBS.

The New York Fed said on its website the Fed sold no mortgage securities guaranteed by Fannie Mae, Freddie Mac or the Government National Mortgage Association, or Ginnie Mae, in the latest week. It sold none the prior week.

At its policy meeting last week, the Fed decided further to reduce its new purchases of MBS in August to $10 billion a month from $15 billion, as the central bank aims to wrap up its third round of large-scale bond buying due to continued improvement in the U.S. economy. The central bank has also continued to reinvest proceeds from interest payments and maturing issues.