The NSW government is revealed to consider imposing fine on private bus operators if they fail to meet agreed performance benchmarks, after a stinging report on the bus transport sector by the state auditor-general.

Auditor Peter Achterstraat on Wednesday described Sydney bus services as "not good enough" and complains that the varied state of services across the metropolitan area.

Private bus operators grabbed severe rebuke, with Mr. Achterstraat revealing that services were infrequent and less accessible than government buses, while operating costs showed a great disparity throughout the service regions.

NSW Transport Minister David Campbell quoted, "The auditor-general's report provides us with some information on which to base negotiations around future contracts".

Mr. Achterstraat seeks the transport department's monitoring of the various regional contracts to become more stringent, with the launch of strict performance benchmarks including service quality and accessibility, addressing the agitation of bus commuters.

Opposition transport spokeswoman Gladys Berejiklian criticized the government for its inability to introduce performance benchmarks for bus operators.