Premier Gladys Berejiklian has pointed to the franchising of Sydney's ferry system as evidence her government is not shielding blue-ribbon Liberal areas from the privatisation of services.

An industrial battle erupted last week after Transport Minister Andrew Constance made the surprise announcement he would privatise the operation of buses in Sydney's inner west, bringing them under the same model that is used in most of western Sydney.

Gladys Berejiklian talks to technicians at the Sydney Institute of Marine Science. Credit:AAP

At the same time, Mr Constance said a new "B-Line" bus service through the lower north shore and northern beaches would be run by the government operator, State Transit.

Asked on Sunday whether, if the privatisation of buses in the inner west proved a success, she would also privatise those in the eastern suburbs and north shore, Ms Berejiklian said: "I don't want to rule anything in or out at this stage.