The Maritime Union of Australia (MUA) says its strike affecting Asciano’s Patrick stevedoring operations will end on Monday.

However, the union pledged to undertake further industrial action if it could not come to an agreement with Asciano in coming days.

Asciano said the dispute over wages and conditions has run for 18 months and resulted in more than 60 stoppages across the Patrick business that cost the company more than $15 million.

“In all likelihood, if we’re unable to reach a common sense position with Patrick, then we’ll be going again,” MUA assistant branch secretary Will Tracey told AAP on Friday.

The union is engaged in a series of strikes at Patrick’s Fremantle container terminal that Asciano said would stop the movement of about 65 per cent of the containers at the port.

The MUA is also involved in a “go slow” at Patrick’s Port Botany operations in Sydney.

Asciano claims the union has refused Fair Work Australia (FWA) to broker negotiations for a new enterprise agreement, adding that the MUA had not negotiated in good faith.

The union says a new agreement would have already been signed if Asciano had simply agreed to the MUA’s demand for FWA to adjudicate disputes between its members and the port operator.

“The reason the talks are breaking down is because Patrick refuse to acknowledge the right for the industrial umpire to resolve disputes,” Mr Tracey said.

“Even the model clause inside the Fair Work Act … has arbitration in the dispute resolution procedure.”

Asciano applied to the FWA for conciliation last week following an 18-month dispute between the union and its ports business Patrick.

The union walked away from the talks on Thursday, Asciano said.

“We are bitterly disappointed that the MUA was not prepared to even clarify its position regarding the few outstanding items,” Patrick director Alistair Field said in a statement on Friday.

“This is an open rejection of good faith bargaining that flies in the face of the Fair Work Act.”

A Fremantle Ports spokeswoman said the other container terminal operator at Fremantle, DP World, was operating as normal.

Fremantle Ports chief executive Chris Leatt-Hayter said the industrial action was having a significant impact on container shipping operations, causing one container ship to bypass the port and head straight on to the eastern states.

“The industrial action will cause significant delays to importers in getting their goods delivered to customers,” Mr Leatt-Hayter said.

“There will also be an impact on exporters who won’t be able to get their goods to international markets.

“The current delays being experienced have potential flow on effects, also, in terms of delays for other vessels scheduled to call at Fremantle to load and unload cargo.”

Separately, the union is also embroiled in an 18-month dispute with Patrick’s maintenance contractor ATIVO.