(Adds dropped word "on" in paragraph 3)
* LME/ShFE arb: bit.ly/2wZSAEz
By Maytaal Angel
LONDON, April 18 (Reuters) - Nickel soared to a three-year peak on Wednesday as what analysts said were misplaced concerns that the metal would become ensnared in U.S. sanctions on Russian companies caused it to break through key technical levels.
Three-month nickel on the London Metal Exchange soared 12 percent at one point to a more than three-year high of $15,875 a tonne, before closing up 7.5 percent at $15,275, its largest daily gain in 6-1/2 years.
Analysts at ING said their sources reported that Chinese traders, nervous about aluminium's soaring rally in the wake of U.S. sanctions on Russia's UC Rusal, misread a headline overnight about the London Metal Exchange delisting Nornickel brands.
Russia's Nornickel is the world's second largest producer of the metal. The LME said last October that on April 18, 2018, it would delist two brands from Nornickel for delivery against its futures contracts.
"It's a misreading of the headline that the (Nornickel) brand is being delisted (today), that decision was taken six months ago, it's nothing to do with the sanctions but when you (spark) a technical rally these things run free," said Oliver Nugent, commodities strategist at ING.
ALUMINIUM: Aluminium ended up 5.5 percent at $2,537 a tonne, having hit its highest in nearly seven years at $2,537.50 after global miner Rio Tinto flagged possible downward adjustments to its 2018 aluminium output following the U.S. sanctions on Rusal.
Concerns over the impact of the April 6 sanctions on Rusal have pushed up aluminium some 25 percent so far.
ALUMINA: Prices of alumina, the raw material for making aluminium, have surged after Rio Tinto last week declared force majeure because of the sanctions on Rusal.
"A source at a smelter ... (is) saying 'phones have been ringing off the hook with people looking for extra metal. They are looking for any extra tonnes, even just a few hundred'," said broker SP Angel.
Goldman Sachs said in a note prices could spike to $2,800-3,000 a tonne but would not stay there. "On a more persistent basis we revise up our 3/6/12-month price forecasts to 2,500/2,300/2,000/t (previously $2,200/1,900/1,950/t)."
NICKEL TECHNICALS: "A weekly close above the horizontal resistance barrier around $14,580/T by the end of this week should be considered bullish, confirming the next stage in the sustainable rising trend," said ING in a note.
INDONESIA EXPORTS: Indonesia exported 8,637,595 tonnes of nickel ore up to March 31, 2018 since its ore export policy was revised in January 2017.
OTHER METALS: Copper ended up 2.1 percent at $7,022 a tonne, zinc closed up 3.5 percent at $3,265, lead closed up 1.2 percent at $2,377 while tin ended flat at $21,475.
Additional reporting by Manolo Serapio Jr., editing by David Evans and Adrian Croft