The Federal Reserve Bank of New York has sold over $4bn of packaged mortgage debt, further reducing a portfolio of assets associated with the bailout of Dutch insurer American International Group (AIG).

Since the sales of the securities was at undisclosed discounts to par value, exact amount of proceeds raised during the auction could not be determined, as reported by Financial Times.

According to the data released by the Federal Reserve Bank, it has accumulated nearly $24.3bn in 2012 to repay loans to Maiden Lane III, from which the underwriter received bailout in 2008.

The US Treasury still holds more than 60% stake in the underwriter, as a part of bailout package provided.

Credit Suisse bought $3.5bn of the securities making it the largest acquirer in the auction, while RBS Securities bought $397m and Morgan Stanley $388m.

According to New York Fed, Maiden Lane III still holds nearly $23bn in face value of securities, which is less than half of the original $62.1bn in face value when the vehicle was set up in late 2008.