MANILA, May 18 (Reuters) - London aluminium futures slipped for a third straight session on Friday as inventories increased, easing worries over a supply shortage in the aftermath of U.S. sanctions on major Russian producer Rusal. On-warrant aluminium stocks in warehouses certified by the London Metal Exchange - inventories that are not earmarked for delivery - surged by 153,075 tonnes or 18 percent on Wednesday, LME data showed on Thursday. MALSTX-TOTAL Three-month aluminium on the London Metal Exchange was down 0.7 percent at $2,277 tonne, as of 0331 GMT, not far above Thursday's two-week low of $2,248.50. "Markets are less worried of a prolonged deficit as Rusal (is) set to boost aluminium exports after the U.S. relaxed its sanctions against Rusal in late April," Commonwealth Bank of Australia analyst Vivek Dhar said in a note. "LME aluminium cancelled warrants are now on par with levels before the sanctions were announced, potentially meaning that we could see some stability at these price levels." About two weeks after imposing sanctions on Rusal, the United States last month gave American customers of Russia's biggest aluminium producer more time to comply with sanctions, and said it would consider lifting them if Rusal's major shareholder, Russian tycoon Oleg Deripaska, ceded control of the company. NICKEL: Nickel outperformed other metals, with the LME price rising to a nearly one-month high of $14,830 a tonne. In Shanghai, the most-traded July nickel contract climbed more than 2 percent to an intraday peak of 110,200 yuan per tonne, its loftiest since June 2015. Nickel is the best performing metal on LME this year, gaining nearly 16 percent so far, with stocks of the metal at LME warehouses at the lowest since July 2014. MNI-STOCKS NICKEL DEFICIT: The global nickel market deficit widened to 15,700 tonnes in March from a revised deficit of 6,600 tonnes in the previous month, the International Nickel Study Group said. COPPER: LME copper dropped 0.2 percent to $6,869 a tonne following a two-day gain. In Shanghai, the most-traded July copper contract on the Shanghai Futures Exchange rose 0.4 percent to 51,280 yuan ($8,051) a tonne. MARKETS: The dollar hit a four-month high against the yen, buoyed by a rise in U.S. Treasury yields that suggests a more upbeat outlook for the world's largest economy. Asian stocks edged up. JINCHUAN: China's Jinchuan Group International Resources plans to double its African copper and cobalt production in the next two to three years. VEDANTA: Vedanta Resources Plc's Thootukudi copper smelter, one of India's biggest, will remain shut until at least June 6.