METALS-Copper extends falls after Chinese economic data

* LME/ShFE arb: http://bit.ly/2wZSAEz (Updates throughout, changes dateline from Melbourne)

LONDON, Oct 19 (Reuters) - Copper prices fell for a third straight day on Thursday after data showed economic growth in China, the world's biggest metals consumer, was in line was expectations.

Investors have taken profits after copper rallied on Monday above $7,000 a tonne for the first time since September 2014, said Danske Bank analyst Jens Pedersen.

"The Chinese data was on balance as expected," he said, predicting Chinese growth would slow into next year and prices would fall to $6,500 by the end of 2017.

COPPER: Benchmark copper on the London Metal Exchange was down 0.7 percent at $6,942 a tonne at 0956 GMT, taking losses since Monday's high of $7,177 to more than 3 percent.

TECHNICALS: Support was at $6,900 and the Fibonacci retracement around $6,850-$6,865, said brokers Marex Spectron in a note.

CHINA ECONOMY: Growth in the world's biggest metals market looked set to accelerate this year after hardly skipping a beat in the third quarter, but efforts to cut risks in property and debt were beginning to weigh.

CHINA FACTORIES: Industrial output rose 6.6 percent in September from a year ago, faster than expected, while fixed-asset investment expanded 7.5 percent in the first nine months of the year, missing forecasts.

CHINA PROPERTY: Property sales dropped for the first time in more than 2-1/2 years in September and housing starts slowed, reinforcing expectations that robust growth is starting to cool.

PARTY CONGRESS: Investors were looking for signals of China's policy direction at a five-yearly Communist Party Congress which began on Wednesday.

CHINA ALUMINIUM: Aluminium output in China fell for a third straight month in September but remained on track for a record high in 2017 despite a government crackdown on polluting smelters.

OUTLOOK: "Production decreased only negligibly month-on-month ... If this means that the decline in production has already come to an end, this points to falling aluminium prices," said analysts at Commerzbank, predicting prices below $2,000 a tonne by the end of 2017. LME aluminium on Thursday was up 0.2 percent at $2,125.50 a tonne.

CHINA STEEL: China's steel output dropped in September from a record high the previous month as mills in the world's top producer cut output as part of a campaign for clearer skies.

PRICES: Nickel was up 0.2 percent at $11,670 a tonne, zinc was 0.8 percent lower at $3,097.50, lead had fallen 0.9 percent to $2,500 and tin was down 0.6 percent at $19,960.

(Additional reporting by Melanie Burton, editing by David Evans)