Primary dealers are responsible for absorbing any supply not bought by direct or indirect bidders. Indirect bidders, which include fund managers and foreign central banks, took 63.92 percent of the supply, higher than 61.27 percent in August and the average of 61.49 percent. Direct bidders took 13.44 percent, higher than the 11.27 percent taken in August, and the auction average of 5.10 percent.

The ratio of bids to the amount of 10-year debt offered - a measure of overall demand - was 2.58, higher than 2.55 in August and the average of 2.38.

The offering was smaller than the $26 billion auctioned in August, but larger than the average of $21 billion at this maturity.