The Treasury sold $6.4 billion in new three-month bills at an average discount rate of 5.85%, down from 5.90% last week. Another $6.4 billion was sold in new six-month bills at an average discount rate of 6.33%, down from 6.35% last week. The rates were the lowest since Dec. 28, when three-month bills averaged 5.73% and six-month bills sold for 6.32%. The new discount rates understate the actual return to investors--6.04% for three-month bills, with a $10,000 bill selling for $9,852.10, and 6.65% for six-month bills selling for $9,680. The discount rate reflects the discount received when government securities are purchased at less than face value.