According to some traders, the transaction, which was done for a domestic account, involved the sale of $1 billion worth of bonds.
Some participants said the results cast doubt on today's sale of $7.5 billion worth of new Treasury notes.
The auctions continue today, with the sale of $7 billion worth of new four-year notes.
A Federal judge awarded them a commission for arranging the 1984 sale of $181 million worth of military uniforms.
The three-year auction will be followed today by the sale of $12 billion worth of new 10-year notes.
The auctions will begin Tuesday with the sale of $9.75 billion worth of three-year notes.
The money will pay for a campaign to urge California voters to approve the sale of $15 billion worth of bonds.
Italy now has to line up investors for a sale of €3bn worth of five-year bonds on Monday.
That auction will be followed tomorrow by the sale of $10 billion worth of two-year Treasury notes.
That auction will be followed on Wednesday with the sale of $9.25 billion worth of new five-year notes.