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 2.195 percent, up from 2.155 percent last week.
An additional $17 billion was sold in six-month bills at a rate of 2.395 percent, up from 2.365 percent.
The new discount rates understate the actual return to investors -- 2.238 percent for three-month bills with a $10,000 bill selling for $9,944.52, and 2.458 percent for a six-month bill selling for $9,878.92.
In a separate report, the Federal Reserve said Monday that the average yield for one-year constant maturity Treasury bills, a popular index for making changes in adjustable rate mortgages, rose to 2.60 percent last week from 2.53 percent the previous week.