Rates fall slightly at US Treasury auction

Interest rates on short-term Treasury bills fell slightly in Monday's auction to their lowest levels in two weeks.

The Treasury Department auctioned $39 billion in three-month bills at a discount rate of 1.00 percent, down from 1.01 percent last week. Another $33 billion in six-month bills was auctioned at a discount rate of 1.11 percent, down from 1.12 percent last week.

The three-month rate was the highest since those bills averaged 0.990 percent on June 12. The six-month rate was the highest since those bills averaged 1.100 percent, also on June 12.

Last week, short-term rates reached their highest levels since October 2008, during the height of the financial crisis. In the preceding week the Federal Reserve had raised its key short-term interest rate for the third time in six months, stamping its latest vote of confidence on a slow-growing but durable economy.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,974.72, while a six-month bill sold for $9,943.88. That would equal an annualized rate of 1.016 percent for the three-month bills and 1.132 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, stood at 1.21 percent on Friday, down from 1.22 percent at the start of last week on June 19.