As had been widely predicted, the Fed said Wednesday it will spend $85 billion a month on bond purchases to drive down long-term borrowing costs and stimulate economic growth. The total includes the replacement of an expiring Fed program with a commitment to purchase $45 billion a month on long-term Treasurys.
Those purchases, and the Fed's renewed commitment to keep interest rates low until unemployment falls to a more normal level, are intended to spur borrowing and spending in an economy still growing only modestly since the financial crisis of 2008.
"As we've seen on numerous occasions recently, the move was already priced into the markets which meant that shortly after the initial spike, prices fell back to their previous levels as traders took profits on their positions," said Craig Erlam, market analyst at Alpari.
"Today we're seeing stocks falling again as they pare gains from the previous days, which again came in anticipation of this decision," he added.
In Europe, markets barely reacted to news that European Union finance ministers had agreed to create a banking supervisor and that Greece has finally been approved to get more bailout cash to avoid bankruptcy. The euro was down 0.1 percent at $1.3060.
The FTSE 100 index of leading British shares was down 0.3 percent at 5,931 while Germany's DAX fell 0.4 percent to 7,587. The CAC-40 in France was 0.1 percent lower at 3,645.
Wall Street was poised for a modest retreat, too, with both Dow futures and the broader S&P 500 futures down 0.1 percent.
The focus in the U.S. will likely remain on the progress of budget discussions between the White House and Congress, which must be agreed by the end of this year to avoid the so-called "fiscal cliff." Without a deal, automatic spending cuts and tax increases could push the world's largest economy back into recession.
Though a deal is expected to be agreed in time to avoid the fiscal cliff, time is running out and some investors are cashing in especially, with the winter holidays round the corner.
"All eyes continue to focus on talks to avert the `fiscal cliff' as negotiators warned that talks could drag on past Christmas as sharp differences remain," said Lee Mumford, a financial sales trader at Spreadex.
Earlier in Asia, Tokyo's Nikkei 225 index jumped 1.7 percent to close at 9,742.73 - an eight-month high - as the yen remained weak against the dollar, a boost for Japan's export-reliant economy. The dollar was up a further 0.2 percent at 83.44 yen.
Hong Kong's Hang Seng shed earlier gains to close 0.3 percent lower at 22,445.50 while South Korea's Kospi rallied 1.4 percent to 2,002.77.
Oil prices tracked equities lower, with the benchmark New York rate down 63 cents at $86.14 a barrel.
(Copyright 2012 by The Associated Press. All Rights Reserved.)