T-Bill Rates Mixed: The Treasury Department sold $10 billion of new three-month bills at an average discount rate of 2.88%, up from 2.82% last week. Another $10 billion of new six-month bills was sold at an average discount rate of 2.95%, down from 2.96% last week. The three-month bill rate was the highest since they sold for 2.89% on April 12. The six-month bill rate was the lowest since Oct. 13, when they also averaged 2.95%. The new discount rates understate the actual return to investors--2.94% for three-month bills, with a $10,000 bill selling for $9,927.20 and 3.04% for a six-month bill selling for $9,850.90. The discount rate reflects the price discount received when government securities are purchased at less than face value.