Union members plan to stop work for 24 hours on Wednesday meaning no trams will run on L1, L2 or L3 tram lines for that day.
From Tuesday, members will not wear uniforms or work overtime and drive at reduced speeds which may impact journey times.
Transdev Sydney Managing Director Arsene Durand-Raucher said he apologised to customers for the planned service disruptions which would impact commuters, schools and Vivid Festival attendees.
“This news will be frustrating for customers, especially post the long weekend, to have to plan around these disruptions,” Mr Durand-Raucher said.
“We are working hard with transport partners to minimise impact to customers caused by this planned industrial action.
“Customers should plan ahead and consider alternate public transport options from this Tuesday or, if possible, avoid non-essential tram travel.
“We’ve alerted schools located near the light rail, and on the day, we will have as many personnel as possible on the ground to help manage the disruption.”
Mr Durand-Raucher said he was disappointed in the planned industrial action after having earlier reached an in-principle agreement last Tuesday.
“We are still committed to negotiating in good faith with our employees through the Rail Tram and Bus Union and met again with bargaining representatives today [6 June],” Mr Durand-Raucher said.
“We remain hopeful that we can reach a resolution and avoid unnecessary disruption.”