Australia's congested container ports face more disruption as the Maritime Union of Australia (MUA) prepares industrial action at one of the country's largest stevedoring companies.

Dock workers employed by the offshoot of Patrick Terminals, which handles more than 40% of Australia's container traffic, will strike for 48 hours in Sydney’s Port Botany this weekend, while those in Melbourne will strike for 12 hours every Monday, Wednesday and Friday during October.