* MSCI world share index down after weak China data
* S&P 500 down slightly after US services data
* Safe-haven bond prices gain ground
By Caroline Valetkevitch
NEW YORK, Jan 6 (Reuters) - World stock indexes dipped on Monday after services sector data in China and the United States revived concerns about slow growth, while gold climbed to its highest in three weeks.
U.S. Treasuries prices extended gains after data showed a private index of U.S. service industry activity unexpectedly fell in December.
That raised questions about whether the Federal Reserve might slow its reduction of bond purchases. The report follows other U.S. data, including one last week on U.S. factory activity, that confirmed underlying strength in the economy and suggested the Fed was justified in deciding in December to begin scaling back its stimulus program.
Outside the United States, figures showing that China's services sector growth slowed sharply last month added to a stack of disappointing data from the world's second-largest economy over the past week.
MSCI's world stock index, which tracks 45 countries, was down 0.4 percent, while all three major U.S. stocks indexes were lower.
The Dow Jones industrial average was down 39.82 points, or 0.24 percent, at 16,430.17. The Standard & Poor's 500 Index was down 5.18 points, or 0.28 percent, at 1,826.19. The Nasdaq Composite Index was down 19.16 points, or 0.46 percent, at 4,112.75.
Traders are still second-guessing the Fed's assessment of recent economic data and how it might alter the U.S. central bank's plan to withdraw its quantitative easing stimulus, said Peter Jankovskis, co-chief investment officer at OakBrook Investments in Lisle, Illinois.
"On balance, today's data is not going to raise concerns the Fed may accelerate the taper," he said.
Wednesday's impending release of the minutes of the December meeting of Fed policymakers and Friday's non-farm payrolls data could give further clues on how quickly the Fed is likely to scale back its huge stimulus program in the coming months.
The U.S. and Chinese data was somewhat offset by positive euro zone data, including some showing gradual recoveries in Italy and Spain. Still, the pan-regional FTSEurofirst 300 slipped 0.2 percent after erasing earlier gains.
The euro zone Composite Purchasing Managers Index, which gauges how thousands of manufacturing and services companies fare every month, rose to 52.1 in December, in line with forecasts, with readings above 50 indicating growth.
The dollar slipped against the euro and yen after the weaker-than-expected data gauging the U.S. services sector.
The euro recovered from a one-month low to trade 0.4 percent higher at $1.3638, while the dollar was last down 0.2 percent to 104.64 yen, according to Reuters data.
In the U.S. bond market, U.S. Treasuries prices rose after the U.S. services sector data spurred bids for government debt.
The benchmark 10-year U.S. Treasury note rose 8/32 in price to yield 2.965 percent, down 3 basis points from late on Friday.
"We had a run of stronger-than-expected data in December that pushed the 10-year yield above 3 percent. We are now seeing some weaker data so we are seeing it falling below 3 percent," said Stan Shipley, bond strategist at ISI Group in New York.
There was plenty of evidence to support the caution China data has fostered among investors.
Figures on Monday showing China's huge services sector slowed sharply in December to its lowest point since August 2011 came hot on the heels of a similar official survey on Friday and two other PMIs last week showing factory activity also soured.
Gold rose to its highest in three weeks, as the dollar and equity markets fell further following the mixed U.S. data, drawing investors to the asset.
Spot gold rose to a three-week peak of $1,248.30 an ounce.
Brent crude oil edged higher on concerns that oil from a recently restarted Libyan field may have difficulty reaching markets amid instability in Iraq.
Brent crude futures for February rose 22 cents to a high of $107.11 a barrel, paring gains from an earlier rise of over $1. U.S. crude fell 16 cents to $93.80 per barrel. The contract lost $1.48 a barrel on Friday and posted its biggest weekly drop since June 2012.