The Treasury sold $6.4 billion in new three-month bills at an average discount rate of 5.64%, down from 5.73% last week. Another $6.4 billion was sold in new six-month bills at an average discount rate of 5.83%, down from 6.03% last week. The rates were the lowest since three-month bills sold for 5.63% on Feb. 8 and six-month bills averaged 5.54% last July 13. The new discount rates understate the actual return to investors--5.82% for three-month bills, with a $10,000 bill selling for $9,857.40, and 6.11% for six-month bills selling for $9,705.30. The discount rate reflects the price discount received when government securities are purchased at less than face value.