Base metals closed mixed in open-outcry trading on the London Metal Exchange (LME) on Tuesday, with negative economic data and a firmer dollar weighing on some, while supply tightness bolstered others, traders said.
"There was a slight correction in copper after the data, and aluminium suffered a small loss on the firmer dollar, but we expect today's losses to be recouped as fundamental and technical factors remain positive," a trader said.
Benchmark three-months copper ended the open-outcry sessions at $2,784 a tonne, down from Monday's late kerb close of $2,826.
An unexpected drop in housing starts in the United States pulled prices lower, while the dollar climbed versus major currencies on expectations that the US Federal Reserve will give an optimistic view for the economy at 1830 GMT.
However, the market was mostly moving in a range while labour talks continued at plants in the United States and Africa.
Workers at Grupo Mexico's La Caridad mine, smelter and refinery in Mexico went on strike a week ago in a dispute over benefits. And workers at the firm's Cananea mine have postponed a strike decision until later on Tuesday in the hope that a resolution with management can be reached.
Contract negotiations are still pending at Grupo Mexico's US unit, Asarco with union leaders set to resume talks with management on August 16.
However, the threat of labour action at South Africa's Anglo American Platinum's (Angloplat) Rustenburg nickel and copper plant subsided after management made an improved offer on bonuses, a union official said.
In aluminium, reduced output at Alcoa Inc's Becancour smelter in Canada were limiting the downside for that market.
Alcoa said has shut two of three potlines at Becancour, cutting annual production to a rate of 135,000 tonnes from 403,000 tonnes.
Unions and management have not been formally talking since the union rejected the company's latest offer last week, and no further talks are planned.
Aluminium ended at $1,720, versus $1,736, while lead edged down.
However, zinc, tin and nickel all edged higher.