Treasury auctions of 30- and 10-year securities drew above-average demand on speculation the Federal Reserve will keep interest rates low for longer than some anticipated amid uneven economic growth.

Both maturities were priced this week at the lowest yields in more than a year. The 10-year note attracted 2.83 times more bids than the amount of debt sold, a demand gauge called the bid-to-cover ratio, and the 30-year bond drew 2.6 times more, both above the averages at the previous 10 auctions. Demand at a three-year note auction lagged behind the longer-term sales.

“The Fed is committed to maintain low yields, even in the face of an improving employment situation,” said Margaret Kerins, the Chicago-based head of fixed-income strategy at Bank of Montreal, one of 22 primary dealers that are obligated to bid in U.S. debt sales. “If you have to put money to work, being long is less scary than being short.” A long position is a bet that a security will rise in price, while a short is a wager it will fall.

The current 30-year bond yield dropped five basis points, or 0.05 percentage point, to 3.19 percent Thursday in New York, according to Bloomberg Bond Trader prices. The yield touched 3.18 percent on Aug. 8, the lowest level since June 2013. The benchmark 10-year note yield fell two basis points to 2.40 percent.

Rate Bets

The likelihood the central bank will boost its benchmark interest-rate target by June declined to 35 percent, from a 51 percent chance on July 31, futures trading showed. The central bank has held the rate in a range of zero to 0.25 percent since 2008 to support the economy.

Treasurys gained Thursday as the Labor Department reported claims for jobless benefits rose to 311,000 last week, the highest level in six weeks. Bonds advanced Aug. 13 after government data showed U.S. retail sales stalled in July in the weakest performance in six months.

The $16 billion long-bond sale Thursday yielded 3.224 percent, compared with a forecast of 3.256 percent in a Bloomberg News survey of eight primary dealers. It was the lowest auction yield since May 2013. The offering’s bid-to-cover ratio beat the average 2.40 at the past 10 sales.

Direct bidders, non-primary-dealer investors that place their bids directly with the Treasury, purchased 24.4 percent of the bonds, the most since October 2011. The average at the past 10 auctions was 15.7 percent.

Indirect bidders, an investor class that includes foreign central banks, purchased 45.9 percent, compared with an average of 44 percent for the past 10 sales.

Note Auctions

Wednesday's auction of $24 billion of 10-year notes drew a yield of 2.439 percent, the least since June 2013. The bid-to- cover ratio topped the 2.69 average at the past 10 sales.

The U.S. sold $27 billion of three-year notes on Tuesday at a yield of 0.924 percent, the least since April. The 3.03 bid- to-cover ratio was the lowest since June 2013.

Thirty-year bonds returned 16 percent this year through Aug. 13, the most in the period since 2010, versus a gain of 3.8 percent by the broader U.S. Treasurys market, according to Bank of America Merrill Lynch indexes. Long bonds lost 15 percent in 2013, versus a 3.4 percent decline by Treasurys overall.

Shorter-term Treasurys didn’t fare as well as investors bet the Fed will raise interest rates at some point next year. Three-year notes have returned 0.9 percent in 2014 after losing 0.1 percent last year, a Bank of America Merrill Lynch index showed.

This week’s $67 billion in note and bond sales raised $9.3 billion of new cash, as maturing securities held by the public totaled $57.7 billion, according to the U.S. Treasury.