Rates mixed at US Treasury auction with 6-month bills rising to highest level in 10 months

Interest rates on short-term Treasury bills were mixed in Monday's auction with rates on three-month bills unchanged and rates on six-month bills rising to their highest level in 10 months.

The Treasury Department auctioned $24 billion in three-month bills at a discount rate of 0.025 percent, the same as last week. Another $26 billion in six-month bills was auctioned at a discount rate of 0.090 percent, up from 0.075 percent last week.

The six-month rate was the highest since those bills averaged 0.110 percent on Feb. 10.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,999.37, while a six-month bill sold for $9,995.45. That would equal an annualized rate of 0.025 percent for the three-month bills and 0.091 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, edged up to 0.15 percent last week from 0.14 percent the previous week.