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By Richard Leong
NEW YORK, Jan 22 (Reuters) - Doubts whether the U.S. Federal Reserve would raise interest rates at all in 2015 lingered on Thursday following the European Central Bank's decision to embark on a bond purchase program to avert deflation spreading across the euro zone.
Short-term U.S. interest rate futures ended lower in a volatile session, suggesting some traders scaled back bets the Fed would refrain from lifting short-term U.S. rates from near zero this year.
The ECB's widely expected stimulus effort, which will involve 60 billion euros a month in bond purchases beginning in March, is seen by some analysts as a possible roadblock for the Fed from normalizing monetary policy, even as the U.S. economy has shown resilience in the face of falling oil prices and economic turbulence abroad.
"The risk grows that the Fed's discussion will go from raising rates to growing its balance sheet," said Justin Hoogendoorn, fixed income strategist at BMO Capital Markets in Chicago.
Fed policy-makers will begin a two-day meeting on Tuesday.
"They are not going to commit to a rate hike," Hoogendoorn said.
In a Reuters poll conducted on Jan. 9, most economists at the top 22 Wall Street firms expect the Fed would raise interest rates by June.
In choppy trading, federal funds futures for December delivery touched a session high of 99.57 before closing lower at 99.545, down 2 basis points from Wednesday's close.
According to CME Group's FedWatch, Dec fed funds futures and options implied traders expected a 76 percent chance of a Fed rate hike in December, up from 74 percent from Wednesday but down from 94 percent a month earlier.
Investors will await whether the Fed will respond to recent stimulative efforts from the ECB and other central banks, analysts said.
Shortly after the ECB's stimulus move, the Danish central bank cut its key policy rate for the second time this week to defend its currency peg to the euro.
On Wednesday, the Bank of Canada stunned markets when it lowered interest rates by a quarter point to 0.75 percent in an attempt to counter the negative impact from the recent drop in oil prices. (Reporting by Richard Leong; Editing by Chizu Nomiyama)