Interest rates on short-term Treasury securities rose in Monday's auction.
The Treasury Department sold $19 billion in three-month bills at a discount rate of 2.155 percent, up from 2.075 percent last week.
An additional $17 billion was sold in six-month bills at a rate of 2.365 percent, up from 2.280 percent.
The new discount rates understate the actual return to investors -- 2.197 percent for three-month bills with a $10,000 bill selling for $9,946.13, and 2.427 percent for a six-month bill selling for $9,881.09.
The average yield for one-year constant maturity Treasury bills rose to 2.53 percent last week from 2.47 percent the previous week.