NEW YORK, Aug 12 (Reuters) - The U.S. Treasury Department on Tuesday sold $27 billion of three-year debt at a yield of 0.924 percent, which was lowest yield since April as investors bought more than half the supply.
The ratio of the amount of bids submitted to the size of the three-year note offering, which is a measure of overall buying interest, was 3.03. That was the weakest since June 2013.
While investors bought about two-thirds of the supply, primary dealers, or the 22 top Wall Street firms that do business directly with the U.S. Federal Reserve, accounted for 36.2 percent of the purchases, which was their smallest share at a three-year note auction since February.
Treasuries yields slightly trimmed their earlier rise after the three-year note auction, which will be followed by a $24 billion auction of 10-year notes on Wednesday and $16 billion in 30-year bonds on Thursday.
These three auctions, which are part of this week's August government refunding, will settle on Friday.
On the open market, three-year Treasuries yield was 0.897 percent, up 0.6 basis point from late on Monday, while benchmark 10-year yield rose 2.2 basis points to 2.442 percent. (Reporting by Richard Leong; Editing by Chris Reese)