Rates mixed at weekly US Treasury auction with 6-month bills rising to highest since late June

Interest rates on short-term Treasury bills were mixed in Monday's auction with rates on six-month bills rising to their highest level since late June.

The Treasury Department auctioned $24 billion in three-month bills at a discount rate of 0.020 percent, unchanged from last week. Another $30 billion in six-month bills was auctioned at a discount rate of 0.060 percent, up from 0.055 percent last week.

The six-month rate was the highest since these bills averaged 0.065 percent on June 30.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,999.49, while a six-month bill sold for $9,996.97. That would equal an annualized rate of 0.020 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.