BEIJING, July 25 (Reuters) - Shanghai copper rose 2 percent to a three-week high in early trade on Wednesday, tracking a rise in London Metal Exchange (LME) prices on Tuesday amid tense negotiations at Chile's Escondida copper mine, the world's largest. Speculation last month about a possible strike at Escondida pushed London copper to a near 4 1/2-year high of $7,348 a tonne on June 7, before fears that a U.S.-China trade war could crimp demand pushed the price below $6,000 tonne last week. FUNDAMENTALS * SHFE COPPER: The most-traded September copper contract on the Shanghai Futures Exchange climbed as much as 2.2 percent to 50,270 yuan ($7,395) a tonne, the highest since July 5, and was up 1.8 percent at 50,070 a tonne as of 0140 GMT. * LME COPPER: Three-month copper on the LME edged down 0.3 percent to $6,278 a tonne, after a 2.7 percent jump in the previous session. * CHILE: BHP's Escondida copper mine in Chile said on Tuesday it had made a final offer in talks with the union representing its rank-and-file workers that includes a beefed up contract signing bonus and a 1.5 percent increase in wages. * OTHER METALS: The Shanghai base metals complex was up across the board, with zinc and nickel both gaining more than 1 percent. * DRC: A computer system used by customs officials in Democratic Republic of Congo had technical problems at the weekend, adding to delays to mining trucks carrying copper and cobalt, sources and officials said on Tuesday. {nL5N1UK2X2] * BRAZIL: Norwegian aluminium producer Norsk Hydro said the timing for resuming full output at its Alunorte alumina refinery in Brazil remained uncertain, with the possibility it could be achieved between October and the middle of next year.