A BHP Billiton spokesperson confirmed to ILN that the company had to take the step because of the disruption to supply caused by the dispute and would outline its impact when it releases its next production report on April 18.

In its last interim report, BHP Billiton said a 15% decline in sales volumes at its Queensland Coal business reduced underlying EBIT by $216 million while higher costs, that partly reflected its flood recovery efforts, reduced underlying EBIT by a further $481 million for the six months to December 2011.

BHP Billiton reported that its Queensland coal business produced 8.4 million tonnes for the three months to December 2011.

“Industrial action and the remnant effects of wet weather continued to constrain the performance of our leading Queensland coal business,” it said at the time.

“While system capability is no longer constrained by the 2011 floods, the extent to which industrial action will continue to impact production, sales and unit costs is difficult to predict.”

The enterprise bargaining negotiations which have dragged on for more than 15 months are now reaching a critical stage, with unions holding meetings today.

The dispute involves seven BMA mines, three unions, and 3500 employees.

Construction, Forestry, Mining and Energy Union representative Stephen Smyth told ILN that the meetings being held with members in the Bowen Basin were to consider the next steps in the dispute.

“We have met with our delegates from all unions and mines [on Friday] in Mackay,” he said.

“They are not happy with the company reneging on the agreed clauses on hours of work, start/finish times and rosters arrangements.

“We met with rank and file members on Monday in Moranbah and Dysart and then Tuesday in Emerald and Blackwater to report back and get their views on things.

“So by [this] week we will be in a position to determine the next steps in this dispute.”