Tensions over Europe's financial problems resulted in another rush of money into Treasury securities, sending yields lower.
The yield on the benchmark 10-year Treasury note fell to 1.73 percent in afternoon trading Wednesday from 1.77 percent late Tuesday. Its price rose 34 cents per $100 invested.
European leaders were meeting in Brussels to hash out ways to promote economic growth and to keep their currency union intact. Spain's prime minister warned that his country can't keep up with its high borrowing costs.
The yield on the 30-year bond fell to 2.82 percent from 2.87 percent. Its price rose 91 cents per $100. The yield on the two-year note fell to 0.26 percent from 0.30 percent.
The yield on the three-month T-bill was 0.09 percent.
The Treasury Department sold $35 billion worth of 5-year notes at a yield of 0.75 percent. Demand was in line with recent auctions.