Australia has announced it plans to block Chinese bidders rom leasing a major Sydney electricity grid on national security grounds.

Treasurer Scott Morrison said Thursday that Chinese state-owned State Grid Corp. and Hong Kong-registered Cheung Kong Infrastructure Group have until next Thursday to respond to his preliminary view that their leasing a 50.4 percent stake in Ausgrid over 99 years would not be in the national interest.

The decision almost certainly sinks the deal for the New South Wales state-owned electricity network that would have earned more than 10 billion Australian dollars ($7.6 billion). The money would have been spent on Sydney rail and road infrastructure projects.

Morrison declined to detail the security concerns raised by the deal.