Construction giant Leighton Holdings is reviewing the value of its investment in troubled Brisbane toll road operator BrisConnections.

BrisConnections, the owner of Brisbane’s airport link toll road, on Monday said its debt may outweigh the value of the company.

The situation had arisen because traffic levels were light following the introduction of tolls for all vehicles on the AirportlinkM7, it said.

Leighton said it was now reviewing the carrying value of its $63 million deferred equity commitment to BrisConnections.

Any impairment on the BrisConnections commitment would be offset by the $115 million gain on the recent sale of the Thiess Waste Management business, Leighton said.

Therefore, a BrisConnections impairment would have no impact on the company’s previously advised underlying net profit forecast of $400 million to $450 million for the year to December 31, it said.