Interest Rates Rise in Treasury Bill Auction

The Treasury Department sold $15 billion in three-month bills at a discount rate of 1.135%, up from 1.1% last week. An additional $16 billion was sold in six-month bills at a rate of 1.135%, up from 1.09%.

The three-month and six-month rates were the highest since March 24, when each type of bill sold for 1.15%.

The new discount rates understate the actual return to investors -- 1.158% for three-month bills, with a $10,000 bill selling for $9,971.30, and 1.161% for a six-month bill selling for $9,942.60.