Treasury prices fell Monday ahead of auctions for $66 billion in government debt scheduled for this week.
The price on the 10-year Treasury note fell 15.6 cents per $100 invested. Its yield, which moves in the opposite direction, rose to 3.51 percent from 3.50 percent late Friday.
Investors have pushed yields on government debt down lately because of the unrest in Libya and concerns that high oil prices will affect the economic recovery. Yields on bonds fall when their prices rise.
The price of the 30-year bond fell 43.7 cents per $100 invested. Its yield inched up to 4.63 percent from 4.60 percent late Friday.
In other trading, the yield on the 2-year note inched up to 0.70 percent from 0.69 percent.
The yield on the 3-month bill dipped to 0.10 percent from 0.11 percent. The discount was 0.10 percent.