WASHINGTON (AP) — Interest rates on short-term Treasury bills were mixed in Monday’s auction with rates on three-month bills rising, while rates on six-month bills were unchanged.

The Treasury Department auctioned $25 billion in three-month bills at a discount rate of 0.025 percent, up from 0.020 percent last week. Another $23 billion in six-month bills was auctioned at a discount rate of 0.045 percent, unchanged from last week.

The three-month rate was the highest since these bills averaged 0.030 percent two weeks ago on April 21.

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 $9,997.73. That would equal an annualized rate of 0.025 percent for the three-month bills and 0.046 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 down to 0.10 percent last week from 0.11 percent the previous week.

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