Three unions – the Maritime Union of Australia, the Australian Maritime Officers Union and the Australian Institute of Marine and Power Engineers – are calling for a seven-day shutdown from tomorrow after failing to reach an agreement with the port’s towage operator Smit.

Notices for consecutive 24-hour stoppages have been filed by the unions.

In a story similar to the deadlock between the Single Bargaining Unit and the BHP Billiton Mitsubishi Alliance, the Gladstone port dispute flared up after months of EA negotiations failed to break an impasse since the previous agreement expired.

Smit is offering a 4.5% annual increase, accompanied by productivity trade-offs, according to The Australian newspaper.

The value of exports through the Port of Gladstone amounted to an average of $169.8 million a week this year, with coal exports making up $120 million of it.

MUA assistant national secretary Ian Bray yesterday told The Australian it was "unfortunate" the union had been forced to consider taking industrial action.

"It's only ever intended to be used as a last resort and we stand by ready to meet with the company if they can find a way to get to the table to continue negotiations," Bray reportedly said.

"We will seriously look at our options in terms of retracting the action on the basis that good-faith negotiations will continue."