Union workers plan to strike later this week at six BHP Billiton- and Mitsubishi-owned coal mines in Queensland, Australia.
The strikes will occur during the night shift at mines from 24 June and will continue with two day shift stoppages early next week.
The unions representing the workers are calling for better pay for apprentices and a reduction in contractors.
The BHP Billiton Mitsubishi Alliance is understood to have withdrawn a proposed A$5000 (US$5,291) bonus offered to workers if they signed up to the new enterprise agreement.
But Queensland president of the Construction, Forestry, Mining and Energy Union's mining and energy division Steve Smyth insisted his members at the mines were unconcerned about the bonus, reports the Australian.
Last week, workers engaged in several six-hour stoppages.