The Maritime Union of Australia has voted to stop work at major container ports in Victoria and NSW.
Container handler DP World says there will be a 32-hour work stoppage at its Melbourne facility on Thursday, while its Sydney terminal will be stopped for 20 hours.
The company's Fremantle port will stop work for four hours also on Thursday.
"This action is occurring at a very busy time and will cause significant schedule disruption leading up to the Christmas period," DP World Australia said in a statement.
"We will work closely with the operators of affected vessels and will explore all options in an effort to mitigate delays.
"We are disappointed that we have been unable to reach a resolution with the MUA."
The company says it negotiated with the union for 12 months before making its eighth offer on Sunday.
The company says it is offering an 11.2 per cent pay rise over four years and a rollover of other conditions including superannuation at 12 per cent.
"That is three times the pay rise granted to the Australian Defence Force and two times that accepted by the likes of nurses, teachers and police officers," the company said.
Comment is being sought from the MUA.
DP World says its offer is open until close of business on Wednesday.
"If it is rejected, we will be applying to the Fair Work Commission to intervene and mediate."
