Rates rise at weekly US Treasury auction; 3- and 6-month bills at highest levels since March

Interest rates on short-term Treasury bills rose in Monday's auction with rates on three-month and six-month bills reaching their highest levels since March.

The Treasury Department auctioned $24 billion in three-month bills at a discount rate of 0.030 percent, up from 0.015 percent last week. Another $24 billion in six-month bills was auctioned at a discount rate of 0.135 percent, up from 0.100 percent last week.

The three-month rate was the highest since those bills averaged 0.035 percent on March 30. The six-month rate was the highest since an average 0.145 percent on March 16.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,999.24 while a six-month bill sold for $9,993.17. That would equal an annualized rate of 0.031 percent for the three-month bills and 0.137 percent for the six-month bills.

Separately, the Federal Reserve said Monday that the average yield for one-year Treasury bills, a popular index for making changes in adjustable-rate mortgages, rose to 0.28 percent last week from 0.26 percent the previous week.