* China GDP grows 6.4%, industrial output surges in March
* World stock markets erase gains as Wall St dips on healthcare
* NZ dollar dives on soft inflation data
* Copper hits 9-month high after China data
* World FX rates in 2019: http://tmsnrt.rs/2egbfVh (Updates to U.S. afternoon trading)
NEW YORK, April 17 (Reuters) - World stock markets gave up early gains as a continued flight from healthcare shares dragged on Wall Street, overshadowing upbeat economic data from China.
The S&P 500 dipped as the healthcare index dived 3.4% to erase its year-to-date gains on continued fallout from concerns about potential changes to U.S. policy, including a "Medicare for All" proposal by Senator Bernie Sanders.
"With a Democrat-controlled Congress, there is definitely more talk on regulating the sector and drug prices, which has negative headline risks," said Matthew Granfki, director of strategy at Los Angeles-based Miracle Mile Advisors.
Mixed corporate results, including a revenue miss from International Business Machines Corp, also contributed to Wall Street's stall, said Stephen Massocca, senior vice president at Wedbush Securities in San Francisco.
"Investors are nervous about the earnings season," he said. "A lot of stocks are heavy right now, even though (the companies) haven't reported yet."
The decline in U.S. stocks weighed on MSCI's 47-country world index, which was buoyed earlier by better-than-expected Chinese data showing the country's economy grew 6.4% in the first quarter.
China's industrial output surged 8.5% in March from a year earlier, the fastest pace since July 2014 and well above forecasts of a 5.9% increase. Retail sales also pleased, with a rise of 8.7%.
Allianz Global Investors strategist and portfolio manager Neil Dwane said the data had been good enough to allay fears that China's economy was collapsing, although the rest of the year remained in question.
"Beijing will now be in a wait-and-see mode to gauge whether it has done enough," Dwane said, referring to stimulus efforts. "To be bullish (on stocks) from here you would have to believe in a pretty strong global recovery in the second half... We are a bit more ho-hum."
The Dow Jones Industrial Average fell 38.44 points, or 0.15%, to 26,414.22, the S&P 500 lost 11.31 points, or 0.39%, to 2,895.75 and the Nasdaq Composite dropped 22.92 points, or 0.29%, to 7,977.31.
The pan-European STOXX 600 index ended 0.1% higher.
MSCI's gauge of stocks across the globe shed 0.16%.
Benchmark 10-year notes last rose 3/32 in price to yield 2.5849%, from 2.594% late on Tuesday.
The euro edged up 0.1% to $1.1294, recovering from losses driven by a Reuters report that several European Central Bank policymakers think the bank's economic projections are too optimistic.
Another currency on the move was the New Zealand dollar , which sank 0.7% to $0.6716 after annual consumer price inflation came in well below expectations, at just 1.5% for the first quarter.
Against a basket of major currencies, the dollar was little changed.
In commodity markets, copper touched a nine-month high on strong Chinese economic data and ended 0.9% higher at $6,556 per tonne.
Spot gold, by contrast, slipped to its lowest for the year. It was last down 0.2% at $1,274.15 per ounce.
Oil prices edged lower, reversing course from earlier gains as U.S. government data showed inventories were drawn down less than an industry report had suggested on Tuesday.
U.S. crude was down 8 cents, or 0.1%, at $63.97 a barrel. Global benchmark Brent crude was 2 cents off its close on Tuesday at $71.70 a barrel.
(Reporting by April Joyner; Additional reporting by Marc Jones, Noah Browning and Zandi Shabalala in London, Amy Caren Daniel and Sruthi Shankar in Bengaluru and Karen Brettell, Stephen Culp, Jessica Resnick-Ault and Stephanie Kelly in New York; Editing by Raissa Kasolowsky, Hugh Lawson, Toby Chopra, Diane Craft and Dan Grebler)