Less than 20 of the striking workers at Chilean copper mine Escondida have abandoned the strike, negotiated contracts individually and returned to work, a union source said Thursday.

"It's about half of those we thought would abandon the strike," said a union representative, who asked not to be named.

On Monday, 38 of some 1,900 voting union members cast their ballot in favour of abandoning the strike. The other 98% of workers voted to reject the company's fourth, sweetened, offer and continue the strike.

With the strike in its 18th day, talks are currently at a stalemate, according to both the company and the union.

"They are at a dead point," the union source said, echoing a similar comment made earlier Thursday by Escondida.
The mine is producing at between 40% and 60% of capacity, a company spokeswoman said, with the company maintaining output using non-union and subcontracted labour.

At the same time, Escondida has not yet decided whether to hire replacement workers as it is entitled to do at this stage, in keeping with Chile's labour laws.

"We're evaluating this as we work to normalize output at the mine," with the decision hinging on the duration of the strike, the spokeswoman said.

A company source laughed the idea off suggestions that the mine, controlled by BHP Billiton (BHP), would bring workers in from its operations in other countries, including neighbouring Peru.

Workers would have to secure work visas, which is not necessarily a speedy process, the source said.

"The speculation can get a little crazy at this point in the strike," he added.

When the strike began, the union secured bank loans for each worker, which would allow them to continue the strike for another month or so, union leaders have said.

The union has also received financial and material support from other mining unions as well as the CUT national umbrella union group.

"Representatives from a Codelco Norte union visited the strikers today, and they've provided food and other goods," the union source said.

Strikes and other work stoppages in the copper mining industry have played a major role in driving the red metal's price higher over the past three years, bolstered by strong demand.