Central bankers appear satisfied with the impact of their latest monetary stimulus, although there is some disagreement over how forcefully to continue purchasing bonds, Reuters reported.

Boston Federal Reserve Bank President Eric Rosengren, one of the most vocal proponents of Fed asset purchases, said there was a "strong case" for the Fed to stay the course on accommodative policies next year and continue buying a total of $85 billion in bonds each month.

In September, the Fed announced an open-ended bond buying scheme that began with $40 billion per month in mortgage-backed securities.

That new effort to boost the economy comes on top of a separate program in which the Fed was buying $45 billion of longer-term Treasury securities per month with proceeds from sales of a like amount of shorter-term debt.

The latter plan, known as Operation Twist, is set to expire at the end of this month, and most analysts expect the central bank to substitute an equal amount of long-term Treasury buying.

Whether to expand the Fed's balance sheet further will be a key topic of debate at Fed policymakers' next meeting on Dec. 11-12. Also under consideration: tweaking Fed communications by adopting numerical thresholds for inflation and joblessness to signal when rates might rise.