* U.S., China tariffs set at lower rates than expected
* China pushes ahead with economic stimulus
* Copper stockpiles fall, market in deficit
* Nickel rises 5 percent, smashes through technical levels (Updates with closing prices)
LONDON, Sept 21 (Reuters) - Copper notched its biggest one-day advance since May 2013 as investors calculated that a trade dispute between the United States and China could damage economic growth less than feared.
Benchmark copper on the London Metal Exchange closed on Friday at $6,363 a tonne, up 4.6 percent, after touching its highest since July. It was up 6.5 percent on the week.
Worries that trade barriers would curb demand for commodities had pushed industrial metals sharply lower, with copper plunging from a high of $7,348 in June to a 14-month low of $5,773 last month.
But these concerns eased after tariffs announced this week were set at lower rates than had been expected and China, the world's largest metals consumer, announced steps to boost its economy.
"There's been quite a change in sentiment," said Saxo Bank analyst Ole Hansen.
But copper would have to move above Fibonacci technical resistance at $6,375 a tonne to cement its rally, he added.
GLOBAL MARKETS: Revived appetite for riskier assets rippled through markets, with global shares hitting six-month highs and Chinese stocks also climbing.
DOLLAR: The U.S. currency, which has been viewed as a safe haven during the trade dispute, was weaker for a second week, supporting dollar-priced metals by making them cheaper for buyers with other currencies.
COPPER STOCKS: Signalling a tightening market, stocks of copper in LME-registered warehouses at 216,600 tonnes are down from nearly 400,000 tonnes in March. <MCUSTX-TOTAL>
Inventories in Shanghai Futures Exchange warehouses fell 17.5 percent to 111,029 tonnes in the week to Friday.
DEFICIT: The global refined copper market showed a 45,000 tonne deficit in June after a 50,000 tonnes deficit in May, the International Copper Study Group (ICSG) said.
SPREAD: Cash copper on the LME flipped from a discount to a premium of $16.50 over the three-month contact <MCU0-3>, suggesting less availability of nearby metal.
NICKEL: LME nickel ended 5 percent higher at $13,250 a tonne, the biggest rise since April. It was at three-week highs and up 4.7 percent on the week
FUNDAMENTALS: Stockpiles are falling in LME and ShFE warehouses and a global market deficit widened in July, the International Nickel Study Group said. <MNISTX-TOTAL>
TECHNICALS: Nickel had broken above the technical and psychological level of $13,000 and a near-term downtrend line coming in at $13,010. It was butting against its 50-day moving average at $13,257.
OTHER METALS: LME aluminum finished up 2.4 percent at $2,091 a tonne, zinc rose 1.7 percent to $2,496, lead ended 1.7 percent up at $2,039 and tin gained 0.2 percent to $19,000.
(Additional reporting by Melanie Burton Editing by David Goodman and Alexander Smith)