Interest rates on short-term Treasury bills rose in Monday's auction to the highest level in two weeks.
The Treasury Department auctioned $15 billion in three-month bills at a discount rate of 1.205 percent.
Another $15 billion in six-month bills was auctioned at a discount rate of 1.245 percent.
The three-month rate was up from 1.190 percent last week. The six-month rate was up from 1.225 percent last week.
The new discount rates understate the actual return to investors -- 1.227 percent for three-month bills with a $10,000 bill selling for $9,969.50, and 1.269 percent for a six-month bill selling for $9,937.10.
In a separate report, the Federal Reserve said Monday that the average yield for one-year Treasury bills, the most popular index for making changes in adjustable rate mortgages, was unchanged last week at 1.46 percent, the same level as the previous week.