MELBOURNE, June 4 (Reuters) - Shanghai copper rallied to the highest in more than six weeks on Monday, underpinned by a slightly softer dollar and supply concerns amid wage negotiations at the world's largest copper mine. The union of workers at BHP's Escondida copper mine in Chile said on Friday it had kicked off the latest round of labour negotiations with a contract proposal that includes a bonus of about $34,000 per worker at the world's largest copper mine. Supply concerns are supportive, however, demand may be pared back as June is typically a quieter month for demand due to summer holidays in the northern hemisphere. "We think LME prices will remain range-bound in June and don't see any major fireworks in the sector in either direction," INTL FC Stone said it a monthly report. FUNDAMENTALS * Shanghai Futures Exchange copper climbed 1.2 percent to 51,930 yuan ($8,090) a tonne, having earlier struck the highest since April 19. * COPPER: London Metal Exchange copper climbed 0.4 percent to $6,920.50 by 0415 GMT, adding to gains in the previous session. Prices earlier rose to $6,964.50, the highest since May 23 and have punched above the 100-day moving average, improving the metal's technical picture. * "I think the spreads tightening is... likely related to jitters about (the) potential union negotiation in Chile for potential strikes in August," a trader said. * TRADE: China warned the United States on Sunday that any agreements reached on trade and business between the two countries will be void if Washington implements tariffs and other trade measures, as the two ended their latest round of talks in Beijing. * U.S. ECONOMY: U.S. jobs growth accelerated in May and the unemployment rate dropped to an 18-year low of 3.8 percent, pointing to rapidly tightening labour market conditions, which could stir concerns about inflation. * STERLITE: Eleven days after police in southern India fired on protesters seeking the shutdown of a copper smelter owned by London-listed Vedanta, killing 13, residents say people suspected of involvement in the demonstrations are being targeted in a wave of arrests. * NICKEL: Premiums for nickel clambered off 15-month lows, rising by $25 to $190 as the price window for imports turned more attractive. Shandong Xinhai Technology Co, one of China's largest nickel pig iron producers, has been told to cut back output ahead of a summit in nearby Qingdao. * COMING UP: U.S. Factory orders for April at 1400 GMT