Transurban has finalised its purchase of a 51 per cent stake in Sydney's Westconnex motorway.

A consortium led by the ASX-listed toll road operator – and including AustralianSuper, the Canada Pension Plan Investment Board and Abu Dhabi-controlled Tawreed Investments – on Thursday reached financial close on the $9.3 billion deal that was agreed with the NSW government in late August.

“We look forward to working with our consortium partners, the NSW Government and the existing team at Sydney Motorway Corporation to complete its construction and ensure that the city gets the most out of this key piece of infrastructure,” Transurban chief executive Scott Charlton said.

The deal had been given the green light to proceed by the competition watchdog after Transurban agreed to publish traffic data that could help rivals bid for future toll road projects and potentially give taxpayers and motorists a better deal.

The NSW government is retaining a 49 per cent stake in the 33km road.

By Alex Druce