BEIJING, June 12 (Reuters) - Shanghai copper slid for the first time in eight days on Tuesday, while London copper continued to lose ground as the dollar strengthened and BHP responded to a proposal from unionised workers at its Escondida copper mine in Chile. A stronger greenback makes dollar-denominated metals more expensive for holders of other currencies and can weigh on prices. FUNDAMENTALS * SHFE COPPER: The most-traded August copper contract on the Shanghai Futures Exchange fell as much as 1 percent to 53,730 yuan ($8,386) a tonne and was trading down 0.8 percent at 0144 GMT. * LME COPPER: Three-month copper on the London Metal Exchange slipped as much as 0.8 percent to $7,196 a tonne. It was trading lower for a third day after hitting a 4-1/2-year high of $7,348 on Thursday. * ESCONDIDA: Global miner BHP, said on Monday it had responded to the latest contract proposal from unionized workers at its Escondida copper mine in Chile, the world's largest, triggering a new round of talks that could last a month or more. * USD: The dollar edged up to a three-week high against the yen on Tuesday, elevated by hopes that the closely watched U.S.-North Korea summit can pave the way towards a reduction in tensions between the two old foes. {nL4N1TE08C] * CANADA: The Canadian province of Quebec will offer C$100 million ($77 million) in loans and guarantees on loans to steel and aluminium companies hit by recent U.S. tariffs, the province's economy minister said on Monday. * VALE: Brazil's Vale on Monday unveiled a $690 million financing to expand a Canadian nickel mine, agreeing to sell unmined cobalt from Voisey's Bay as a booming electric vehicle market propels demand for the critical battery ingredient.