The tram extension to Dulwich Hill should open in March, Transport Minister Gladys Berejiklian has said, as long as no problems emerge during track testing.

But commuters using the new service may have to wait for service frequencies to increase, as the government awaits the delivery of another 10 trams in the next 18 months.

"The frequency we have to start with is only going to increase." Gladys Berejiklian. Credit:Quentin Jones

Ms Berejiklian announced on Wednesday major construction of the nine new light rail stops between Lilyfield and Dulwich Hill was now completed, and the tracks and infrastructure were ready.

The only thing left to do is test the vehicles, on what will be the first major piece of public transport infrastructure opened under the O'Farrell government.