BHP Billiton has launched legal action against the Maritime Union of Australia for $7 million the mining giant claims was lost through a four hour “illegal” strike at a major iron ore port in the Pilbara.

BHP Billiton filed a writ on the MUA and its West Australian assistant branch secretary William Tracey on June 28 claiming the short strike by workers at the Port Hedland port on March 9 had cost millions in lost business.

A Port Hedland Port Authority spokesman said only two vessels missed their windows on the morning tide on March 9, one ship was from a FMG berth, which went on to sail 12 hours late.

More at Business Day