BEIJING, July 6 (Reuters) - London copper fell for a fifth straight session on Friday and hit a fresh 11-month low as U.S. tariffs on Chinese goods kicked in, escalating the trade spat between the world's top two economies. Copper, seen as a bellwether for economic health, is down 5.5 percent in London this week, putting it on track for its steepest weekly drop since the week ended Jan. 16, 2015. The United States imposed tariffs on $34 billion of Chinese imports at 0401 GMT. Beijing has promised to retaliate in kind. The U.S.-China trade dispute "looks like becoming entrenched" and "comes at a time when copper demand suffers its seasonal slowdown," ANZ wrote in a note. "However, we feel the market is oversold. Supply disruptions remain a threat, and shifts in China's consumption patterns will see demand for refined copper remain strong," it said. "If trade tension subsides, we would expect copper prices to recovery strongly" in the second half of 2018, ANZ said. FUNDAMENTALS * LME COPPER: Three-month copper on the London Metal Exchange fell as much as 2 percent to $6,221.50 a tonne, its lowest since July 25, 2017. It has declined in nine of the past 10 sessions. * SHFE COPPER: The most-traded August copper contract on the Shanghai Futures Exchange dropped as much as 2.2 percent to 48,520 yuan ($7,296.02) a tonne, the lowest since July 17, 2017. It is down 5.2 percent for the week, which would be the worst since January 2015. * ESCONDIDA: Negotiations between workers and BHP Billiton Plc, at the Escondida copper mine in Chile, the world's largest, are "far from reaching agreement" with less than three weeks to go before the negotiation deadline, a union official told Reuters on Thursday. * ZINC: Shanghai zinc fell as much as 1.1 percent, while London zinc declined as much as 0.9 percent amid rising supply. London zinc is down around 5.5 percent this week, the most since December 2016. * ALUMINIUM: Shanghai aluminium was up 0.3 percent as Chinese alumina refiners cut production, while London aluminium was down 0.1 percent.