MELBOURNE (Reuters) - Tug boat captains at Australia's top iron ore export port have approved plans to go on strike for up to three days in a fight for better pay, which could halt a quarter of the world's iron ore exports.
Australian Maritime Officers Union members overwhelmingly approved eight different proposals ranging from a two-hour to a 72-hour work stoppage, a spokeswoman for the Fair Work Commission said on Friday.
The vote by the Australian Maritime Officers Union follows approval by tugboat deckhands to strike for up to a week. Neither group has set a date for a strike and the deckhands have said they would hold off until at least late June while they try to resolve issues with tugboat operator Teekay Shipping (TK.N).
The tugboats guide iron ore carriers in and out of Port Hedland, which handles more than half of Australia's iron ore exports. The strike threat comes as producers have been ramping up output, which has led to heavier ship traffic.
The unions have come under pressure to compromise with Teekay, as any strike would result in the loss of $100 million a day in iron ore sales and millions in royalties and taxes to the state of Western Australia and the country.
Tugboat engineers are holding a separate vote to strike for up to two days. Their ballot result is due on June 10.
Teekay and the unions are due to hold another mediation session on June 5.
Reporting by Sonali Paul; Editing by Richard Pullin