The Treasury Department sold $6.8 billion in new three-month bills at an average discount rate of 6.52%, down from 6.55% last week. Another $6.8 billion was sold in new six-month bills at an average discount rate of 6.55%, up from 6.54%. The three-month rate was the lowest since June 16, 1980, when it was 6.37%. The new discount rates understate the actual return to investors--6.72% for three-month bills and 6.87% for six-month bills. The discount rate reflects the price discount received when government securities are purchased at less than face value.