As an added benefit, the relatively new Oscar outer suburban fleet currently used on these services will be transferred onto SydneyTrains suburban routes to replace the last of the older non-air conditioned rolling stock still in service in the Sydney area.

The state government says it wants to work with the world's leading rolling stock manufacturers to identify the best available platform, selecting an existing design to ensure the first trains enter service within the next four to five years.

Transport minister Mrs Gladys Berejiklian said the trains will be funded by the NSW government and the procurement process will begin soon, with industry briefings set to take place in the coming weeks.

"We are looking at buying off-the-shelf trains with proven technology and then configuring them to meet our customers' needs, meaning we can ensure the best value, best possible service and also have these new trains on the tracks faster," she says. "We expect the first train will be in passenger service by 2019 and the new fleet will be progressively rolled out by 2024."

Berejiklian also said that infrastructure improvements might be considered to improve journey times.

There has been no indication yet as to whether the new EMUs will be similar to traditional Sydney double-deck stock or if single-deck trains will be procured. This has been the subject of recent debate in New South Wales.