All services on the present timetable would remain, though some trains would arrive slightly earlier or later at some stations.

The new timetable was aimed at addressing crowded peak-hour trains in Sydney, by providing extra peak-hour services and carriages, and incorporated the new Epping to Chatswood rail link.

CityRail said it would introduce a new timetable for the Eastern Suburbs, Illawarra and South Coast lines after completion of the Cronulla Line duplication - which is not due until 2010.

"As part of ... this timetable new services will be introduced and stopping patterns will be reviewed," CityRail said.

Customers will have a chance to comment when the timetable becomes available.