Transurban is buying $475 million of debt held by Sydney’s Cross City Tunnel as it looks to take control of the troubled toll road.

The 2.1 kilometre tunnel, which connects the west side of Sydney’s CBD to Rushcutters Bay in the east, has had a troubled financial run since its opening in 2005.

Its current owners, Royal Bank of Scotland, EISER Infrastructure Partners and Leighton Contractors, bought the toll road in 2007 after it was placed into receivership by its original owners.

But the tunnel was placed into receivership again in September in the wake of a legal dispute with the NSW government over stamp duty.

Transurban on Monday announced it would buy all of the toll road’s senior debt from the Royal Bank of Scotland for $475 million.

Transurban already owns or part-owns several major toll roads in Sydney – the M2, M5 and M7 motorways, the Lane Cove Tunnel and the Eastern Distributor, which links to the Cross City Tunnel.

The debt purchase is subject to regulatory approval, but Transurban and RBS have instructed the tunnel’s receivers to continue to work towards the sale of the asset while the deal was being finalised.

Transurban chief executive Scott Charlton said the company intends to bid for the tunnel during the sale.

“The acquisition of the senior debt in the CCT (Cross City Tunnel) will allow us to work with the receivers to examine restructuring options for the asset and, ultimately, if successful in the sale process, put the asset onto a sustainable footing,” he said.

Ratings agency Moody’s said the debt purchase would weaken Transurban’s financial metrics, but it is not expected to affect its credit rating, which is currently Baa1.

Transurban said its distributions to shareholders would not be affected.