Interest rates on US Treasury bills mixed at weekly auction

Interest rates on short-term Treasury bills were mixed in Monday's auction with rates on three-month bills unchanged while rates on six-month bills rose to their highest level in nine years.

The Treasury Department auctioned $42 billion in three-month bills at a discount rate of 1.050 percent, unchanged from last week. Another $36 billion in six-month bills was auctioned at a discount rate of 1.190 percent, up from 1.170 percent last week.

The six-month rate was the highest since those bills averaged 1.400 percent on Oct. 27, 2008.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,973.46 while a six-month bill sold for $9,939.84. That would equal an annualized rate of 1.067 percent for the three-month bills and 1.214 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 1.31 percent Friday, little changed from a level of 1.30 at the beginning of last week on Sept. 25.