WASHINGTON - Interest rates on short-term Treasury bills rose in Monday's auction to the highest levels in four weeks.

The Treasury Department auctioned $24 billion in three-month bills at a discount rate of 0.165 percent, up from 0.150 percent last week. Another $25 billion in six-month bills was auctioned at a discount rate of 0.245 percent, up from 0.240 percent last week.

The three-month rate was the highest since three-month bills averaged 0.175 percent four weeks ago on April 5. The six-month rate was the highest since these bills averaged 0.265 percent, also on April 5.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,995,83, while a six-month bill sold for $9,987.61. That would equal an annualized rate of 0.167 percent for the three-month bills and 0.249 percent for the six-month bills.

ASSOCIATED PRESS