Bids on six-month bills produced an average discount rate of 7.21 percent, down from 7.33 percent a week ago.
Bids at the auction produced the lowest rates in nearly two months.
Bids on the new six-month bills produced an average rate of 5.47 percent, compared with 5.23 percent a week ago.
Bids from 24 firms produced an average rate of 5.968 percent for the notes, which mature June 28, 1991.
Bids on new six-month bills produced an average discount rate of 5.72 percent, unchanged from a week ago.
Bids produced an average yield of 8.54 percent.
Bids for the new six-month bills also produced an average discount rate of 6.01 percent, up from 5.91 percent a week ago.
Bids on six-month bills produced an average discount rate of 6.21 percent, unchanged from a week earlier.
Bids at the auction produced an average yield of 8.77 percent, the highest such rate in more than two years.
Bids on six-month bills produced an average rate of 7.16 percent, down from 7.22 percent at last week's sale.