Greek construction groups Ellaktor and Avax now operate the Attica Motorway, a 70-km (44-mile) road bypassing a usually congested Athens centre.

The country has shortlisted eight investors, including Vinci and Macquarie, as part of a tender to extend the contract for another 25 years after it expires in 2024.

?he process will wrap up with the submission of binding bids for which the deadline is still unspecified.

Following a decision by the infrastructure ministry, the binding bids should be based on the assumption that users will be charged 2.5 euros ($2.60) per vehicle, Greek Infrastructure Minister Kostas Karamanlis said in a statement on Friday.

Under the current contract, drivers are paying a single charge of 2.8 euros for all routes once they enter the highway.

($1 = 0.9608 euros)

(Reporting by Angeliki Koutantou, Editing by Louise Heavens)