Rates mixed at weekly US Treasury bill auction with 3-month bills down to lowest since April

Interest rates on short-term Treasury bills were mixed in Monday's auction, with rates on six-month bills unchanged while rates on three-month bills dropped to the lowest level since late April.

The Treasury Department auctioned $25 billion in three-month bills at a discount rate of 0.025 percent, down from 0.030 percent last week. Another $23 billion in six-month bills was auctioned at a discount rate of 0.060 percent, unchanged from last week.

The three-month rate was the lowest since three-month bills averaged 0.020 percent on April 28.

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 $9,996.97. That would equal an annualized rate of 0.025 percent for the three-month bills and 0.061 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, was 0.11 percent last week, unchanged from the previous week.