In just the first week of the Federal Reserve's initiative to acquire additional agency mortgage-backed securities, the open market trading desk in New York saw gross purchases reach $21.9 million.

Total sales for the period reached $1.8 million while net purchases totaled $20.1 million.

The data provided by the Federal Reserve Bank of New York Thursday covers only the seven-day period stretching from Sept. 20 through Sept. 26. It also reflects a rather small portion of what the Fed will be acquiring in agency MBS each month.

Federal Reserve Chairman Ben Bernanke announced a third round of quantitative easing earlier this month. The open-ended plan includes the acquisition of $85 billion in longer-term securities every month as well as $40 billion in MBS.   

The Federal Open Market Committee directed the open trading desk at the Federal Reserve Bank of New York to begin acquiring agency MBS at a pace of $40 billion per month on Sept. 13.