Market and product

London copper fell on Friday and selling spilled into other metals, after results from Britain's referendum signaled it was on a path to leave the European Union.

Britain has voted to leave the European Union, the BBC said based on voter tallies from Thursday's referendum, an outcome that would put the country on uncertain ground and deal the largest setback to European unity since World War Two.

"For the metals, I think the market has been relatively muted from Asian investors. I'd suspect you'd probably get another wave of selling as London wakes up," said analyst Dan Hynes of ANZ in Sydney.

"I don't discount some impact in the very short term, but fundamentally, once it settles down I can't see things being too different from where we were a week ago," he said.

Three-month copper on the London Metal Exchange fell as much as 4 percent before trimming losses to about 3 percent at $4,643 a ton by 0406 GMT.

The session has been marked by wild swings that at one point had copper at its biggest daily slide since July last year. On Thursday, it had touched its highest since May 6 at $4,795.

The drop erased most of a weekly advance that had been sparked by a fall in the dollar as expectations grew that the U.S. would delay its next interest rate hike after its economy stumbled in the first quarter.

Selling also spilled into other metals, with nickel stumbling more than 4 percent, while LME aluminum, tin, lead and zinc dropped 2-3 percent.

The number of Americans filing for unemployment benefits fell last week to near a 43-year low, however, while other data also gave a fairly upbeat assessment of the U.S. economy after it stumbled in the first quarter.

In Shanghai, the impact from the "Brexit" vote was less severe. Shanghai Futures Exchange copper fell to 36,050 yuan ($5,455) a ton, a drop of 0.4 percent, having gained 1.3 percent in the previous session. ShFe nickel fell 2.4 percent, and most other metals were down less than a percent.

Fundamentally for copper, supply was set to climb with Zambia's copper production to rise by 5.5 percent to 750,000 tonnes this year and output expected to double to 1.5 million tonnes in 2017, its mines minister said.

Elsewhere, the incoming minister in charge of Philippine mining slammed the use of open pits to extract minerals, describing it as "madness" even to consider the method because of the environmental impact.

Philippines is the biggest supplier of nickel ore to China, which uses it to make stainless steel.