* China October power grid investment dips
* Nickel gains amid uncertainty on supply
* Copper 2014 term deals seen at China CESCO next week
* Coming up: U.S. Industrial output at 1415 GMT
(Updates with official prices)
LONDON, Nov 15 (Reuters) - Copper hovered near three-month lows on Friday on persistent worries about the tapering of monetary stimulus in the United States and after data showed a slowdown in infrastructure spending in the Chinese power sector.
Copper, set for its biggest weekly drop since late August, fell below a three-month range this week as prolonged worries over the timing and scale of tapering crimped appetite for risk.
Three-month copper on the London Metal Exchange reversed early gains in Asian trading to fall 0.4 percent to $6,965 a tonne in official midday trading.
The price, poised to fall around 3 percent for the week, was within reach of its trough on Thursday of $6,940 a tonne, the lowest since Aug. 7.
While falling prices have largely met with solid consumer demand, leading indicators were not as positive, said analyst Gayle Berry at Barclays in London.
Chinese investment in its power grid, which accounts for about 40 percent of its overall copper demand, fell by 14 percent in October, a second straight monthly decline.
"The power grid data is a red flag. It appears to tell us that over the next three to six months we should see quite a sharp slowdown in Chinese copper consumption growth," Berry said.
"There's a divergence between what the leading indicators are telling us and what actual consumption is doing in China, which has been holding up quite strong."
Near-term indicators for Chinese consumption are buoyant, said analyst Joel Crane of Morgan Stanley in Melbourne, pointing to industrial power consumption and auto output. "Prices are likely to eventually recover once this technical-based rout has run its course."
The most-traded February copper contract on the Shanghai Futures Exchange marked a new three-month low, closing at 50,080 a tonne, down 0.87 percent.
Premiums for term shipments of copper to China are expected to be hammered out in Shanghai next week at an industry gathering. Miners will also be negotiating with smelters on processing charges.
SUPPLY RISK IN NICKEL
Nickel prices rose as much as 1.3 percent to a session high of $13,830 a tonne amid an uncertain environment about supply. It failed to trade in official rings and was last bid at $13,735, up 0.6 percent.
Indonesia, which accounts for 20 percent of global nickel supply, has said it will ban exports of unprocessed ore in January.
"As every day goes by, that Indonesia export ban deadline gets closer and closer. For me that's one of the biggest supply risks the industry is facing over the next few months," Berry said.
"There's a lot of scepticism within the industry about whether the ban will be fully implemented, but the risk is that perhaps the market is being a bit too complacent."
News also emerged this week of a mine closure in Australia following an earthquake.
On Friday, Finnish nickel miner Talvivaara filed for a court-supervised overhaul without which it risked bankruptcy.
In other metals, aluminium fell 0.3 percent in official trading to $1,785 a tonne, and lead lost 0.2 percent to $2,091.
Tin and zinc also failed to trade in official rings. Tin was last bid at $22,940 a tonne, down 0.3 percent, and zinc was last bid at $1,889, up 0.2 percent. ($1 = 6.0922 Chinese yuan)
Three month LME copper
Most active ShFE copper
Three month LME aluminium
Most active ShFE aluminium
Three month LME zinc
Most active ShFE zinc
Three month LME lead
Most active ShFE lead
Three month LME nickel
Three month LME tin
(Additional reporting by Melanie Burton in Singapore; editing by William Hardy and Jane Baird)