The Treasury Department sold $7 billion in new three-month bills at an average discount rate of 7.2%, up from 7.14% last week. Another $7 billion was sold in new six-month bills at an average discount rate of 7.36%, up from 7.32% last week. The rates were the highest since Sept. 9, when three-month bills sold for 7.22% and six-month bills averaged 7.39%. The new discount rates understate the actual return to investors--7.44% for three-month bills and 7.75% for six-month bills. The discount rate reflects the price discount received when government securities are purchased at less than face value.