Rates rise at weekly US Treasury auction with 6-month bills hitting highest level since March

Interest rates on short-term Treasury bills rose in Monday's auction, with rates on six-month bills climbing to the highest level since late March.

The Treasury Department auctioned $24 billion in three-month bills at a discount rate of 0.015 percent, up from 0.010 percent last week. Another $24 billion in six-month bills was auctioned at a discount rate of 0.110 percent, up from 0.080 percent last week.

The three-month rate was the highest since those bills averaged 0.020 percent on May 11. The six-month rate was the highest since those bills averaged 0.135 percent on March 30.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,999.62, while a six-month bill sold for $9,994.44. That would equal an annualized rate of 0.015 percent for the three-month bills and 0.112 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 0.29 percent last week from 0.27 percent the previous week.