Fears that Greece will drop the euro pushed a key Treasury yield to the lowest level this year.
The yield on the 10-year note dropped to 1.76 percent in Wednesday trading, a new low for 2012. That's down from 1.77 percent late Tuesday. Its price rose 12.5 cents for every $100 invested.
The 10-year yield is widely used as a benchmark for mortgages and corporate loans.
Greece's president said 700 million euro ($891 million) had been pulled out of the country's banks, adding to worries about its weakened financial system. That news was followed by a report from Reuters that said the European Central Bank had stopped providing funds to some Greek banks.
The prospect of a wider financial crisis if Greece leaves the European currency union has kept traders in U.S. Treasurys and other assets considered safe.
Other Treasurys were little changed from the day before. The yield on the 30-year bond slipped to 2.90 percent from 2.92 percent late Tuesday. Its price rose 37.5 cents. The yield on the two-year note remained at 0.29 percent.
In the market for short-term Treasury bills, the yield on the three-month T-bill was 0.10 percent.