The 10-year T-note last yielded 1.40 percent, up from a record low of 1.3808 percent set on Wednesday.
Treasury yields have been pushed down by the global growth concerns, worries Spain will need a massive financial bailout on top of a bank rescue plan, and concerns that Greece's debt woes could eventually force it to exit the euro zone.
"We've got supply in the seven-year part of the curve and the market is setting up a little bit for that, trying to get some concession. We've seen selling of fives and sevens," a trader said.
Some analysts said yields could drop further once the supply was out of the way as the mood in the euro zone remains fragile.
The seven-year notes due for sale yielded 0.91 percent in the when issued market broadly in line with the 0.91 percent yield on the current seven-year note in the secondary market.
The auction caps $99 billion euros in new debt sales by the Treasury Department this week. A total of $35 billion of five-year notes were sold on Wednesday at a record low yield, following a record low yield in the sale of $35 billion of two-year notes on Tuesday.
The yield on 30-year T-bonds stood at 2.44 percent , around the previous session's trough of 2.447 percent.