NEW YORK - World stock markets mostly edged lower on Tuesday after the OECD cut its global economic growth forecasts, raising concerns that a recent rally may be overdone.

Questions over when the Federal Reserve might trim its stimulus added to the uncertainty, with commodities lower on the day and the US dollar volatile. However, the Fed's program is expected to continue providing a floor to equity prices so long as it continues, helping to limit declines.

In its latest snapshot of economic activity, the Paris-based Organization for Economic Cooperation and Development cut its 2014 forecast for global economic growth to 3.6 percent from the 4.0 percent it saw in May.

Equity investors are concerned that the recent rally, which has taken indexes to all-time highs and has been fueled by accommodative monetary policies from central banks around the world, has outpaced underlying economic improvement.

"There's no real news to propel the market higher but no real options for investors in terms of other places to put their money," said Rick Meckler, president of investment firm LibertyView Capital Management.

"The market will likely stay here until the beginning of next year and the Fed decides when is a good time to change policy."

MSCI's world equity index, which tracks shares in 45 countries, fell 0.3 percent, backing away from a six-year peak hit on Monday.

The Dow Jones industrial average was up 6.10 points, or 0.04 percent, at 15,982.12. The Standard & Poor's 500 Index was down 1.97 points, or 0.11 percent, at 1,789.56. The Nasdaq Composite Index was down 1.48 points, or 0.04 percent, at 3,947.58. The benchmark 10-year U.S. Treasury note was down 4/32 in price, with the yield rising to 2.6907 percent.

In Europe, shares fell 0.6 percent, receding from a recent five-year high.

"Pan-European multiples are close to multi-year highs. That means markets are no longer cheap and we need to see some earnings improvement to warrant higher equity prices," said Gerhard Schwarz, head of equity strategy at Baader Bank.

Earlier, optimism sparked by China's bold economic reform plans had continued to bolster Asian markets, lifting MSCI's index of Asia-Pacific shares outside Japan by 0.2 percent, extending Monday's 1.4 percent rally.

DOLLAR FLAT

The dollar held steady on Tuesday, caught between talk the U.S. central bank could keep its easy policy stance until March of next year and some optimistic comments on the economy by two top Fed officials that could signal an earlier move.

William Dudley, president of the New York Fed and one of the staunchest supporters of the Fed's easy-money policies, cited labor market improvements and stronger-than-expected growth in the third quarter as positive signs for the U.S. economic recovery.

The mere hint that a December tapering is still possible was enough to keep the dollar index steady against six other major currencies at 80.80. The dollar was flat against the yen at 100.03 yen, while it eased slightly against the euro .

Euro zone government bonds moved within narrow ranges with 10-year German yields slightly firmer at 1.7 percent, while lower-rated Spanish and Italian yields were little changed.

In commodity markets, copper rose 0.2 percent while gold was flat. U.S. crude oil futures fell 0.3 percent while Brent crude lost 0.7 percent.