BEIJING, Sept 5 (Reuters) - Shanghai copper hit its lowest
in more than a year overnight and was down for a fifth straight
day on Wednesday, tracking a 2.6 percent drop in London copper
as U.S.-China trade tensions continued to weigh on metal prices.
    Open interest in Shanghai copper, a measure of market
liquidity, on Tuesday hit its highest since July 18, as futures
brokerages added a total of 3,047 lots to their short positions
on the October contract. Shorts outnumber longs on every
contract until at least January.
    The Shanghai copper futures curve remains in backwardation
till January, a sign of higher immediate demand, with China
copper premiums SMM-CUYP-CN still near a 22-month high.    
    All other Shanghai base metals dropped with the exception of
tin, which eked out a 0.5 percent rise.
    "There appears no let-up in the selling in base metals amid
the stronger USD, ongoing trade tension and emerging market
turmoil," ANZ said in a note. 
    * SHFE COPPER: The most-traded October copper contract on
the Shanghai Futures Exchange fell as much as 2 percent
in the night session to 47,040 yuan ($6,881.72) a tonne, its
lowest since June 2017. It was trading down 1.4 percent at
47,320 yuan a tonne by the mid-session interval.
    * LME COPPER: Three-month copper on the London Metal
Exchange snapped a five-day losing streak to trade up
0.5 percent at $5,844 a tonne, as of 0400 GMT, as the dollar
index edged down from a two-week high, making metals
slightly cheaper for holders of other currencies.
    * OTHER METALS: Shanghai nickel dropped 2.1
percent, after hitting its lowest since April 24 overnight,
while zinc, which is down 17.3 percent year-to-date,
lost 2.2 percent and lead slumped 1.7 percent.
    * WAREHOUSING: Some warehouse firms want the London Metal
Exchange to change its rules for delivering material so as to
allow longer queues and boost revenues undermined by falling
stocks, sources familiar with the matter said.
    * ALUMINA: A vote by striking workers at Alcoa's
giant west Australian operations will close on Thursday, with
the union anticipating a strong "no" vote that could prolong the
four-week old strike.