The Treasury Department sold $7.4 billion in new three-month bills at an average discount rate of 6.09%, down from 6.11% last week. Another $7.4 billion was sold in mew six-month bills at an average discount rate of 6.13%, down from 6.18% last week. The new discount rates understate the actual return to investors--6.27% for three-month bills and 6.41% for six-month bills. The discount rate reflects the price discount received when government securities are purchased at less than face value. Also, the Federal Reserve said the average yield for one-year T-bills was 6.61% last week, down from 6.85%.