(New throughout, adds details, union comments; adds byline, changes dateline, previous SANTIAGO)
By Felipe Iturrieta
ANTOFAGASTA, Chile, March 22 (Reuters) - Leaders of the striking union at BHP Billiton's Escondida mine in Chile will meet with the rank-and-file before making any additional decisions about negotiations, a union spokesman said after exiting a meeting with BHP on Wednesday.
BHP and leaders of the 2,500-member union at Escondida, the world's largest copper mine, left the meeting in the city of Antofagasta without offering additional comment, or saying when the parties would next sit down.
"No comment, we're going to meet with the base," union spokesman Carlos Allendes told reporters.
Since workers walked off at the massive deposit on Feb. 9, copper production has been stopped, sending global copper prices higher amid supply concerns.
Talks have since been tense, and various attempts to return to the negotiating table have failed. The two parties finally returned to the table on Monday for the first time in weeks, and met again on Wednesday afternoon.
Earlier on Wednesday, BHP decided to suspend work indefinitely at projects linked to Escondida, such as construction work at its Coloso desalinization plant and its Los Colorados concentrator, citing continued blockades by the union.
Throughout the process, workers have maintained three core demands: that the benefits in the previous contract not be reduced; that shift patterns not be made more taxing; and that new workers get the same benefits as those already at the mine.
The union has also said in recent days that it could invoke an article of Chile's labor code that would stop the current negotiations and send the miners back to work for 18 months under the previous contract. They said that would allow them to start negotiations again under new labor laws set to go into effect in Chile in April, strengthening their hand.
Escondida is majority controlled by BHP, with minority participations by Rio Tinto and Japanese companies including Mitsubishi Corp. It produced slightly more than 1 million tonnes of copper in 2016. (Reporting by Felipe Iturrieta; Writing and additional reporting by Gram Slattery in Santiago; Editing by David Gregorio)