(Reuters) - Republican presidential candidate Mitt Romney said on Sunday that a fresh round of monetary stimulus from the Federal Reserve would not help the fragile U.S. economy.

A stream of disappointing economic news has underpinned expectations that the central bank will do more to stimulate growth with a third round of bond purchases, also known as quantitative easing or QE3.

"I am sure the Fed is watching, will try to encourage the economy, but I don't think a massive new QE3 is going to help this economy," Romney said in an interview with CNN's "State of the Union" television program that was aired on Sunday.

"The Fed's first action, quantitative easing was effective to a certain degree. But I believe that the QE2, the second round of easing, I don't think it had the impact that they were hoping for," he said.

Romney, who has been stressing his business acumen and years as Massachusetts governor as reasons he can help heal the economy, has vowed to create 12 million jobs in his first four years in office should he beat Democratic President Barack Obama in the November election.

The unemployment rate ticked up to 8.3 percent in July, a reported released last week showed, prompting Romney to tear into Obama's handling of the economy, a key election issue.

On Wednesday, the Federal Reserve signaled that a new round of major support could be on the way if the recovery does not pick up.

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