The Berejiklian government has pushed ahead with the privatisation of bus services in Sydney's inner west, confirming Transit Systems will take over from the state-run operator in July.

The move has infuriated the Rail Tram and Bus Union which claims privatisation of bus region six – covering suburbs from Kensington in the city's south-east to Strathfield and Olympic Park in the west – will lead to fewer stops and buses and longer journey times.

"That is exactly what has happened in Newcastle after the government sold off their buses. It will certainly happen here,” the union's divisional secretary, Chris Preston, said. “This is yet another captain’s call from the Transport Minister."

The new contract covering bus services in Sydney's inner west will begin in July. Credit:Peter Rae

But Transport Minister Andrew Constance said the awarding of the tender to Transit Systems would in fact result in extra services on four of the region's busiest bus routes.