Portugal will start negotiating with France’s Vinci about building and running Lisbon’s €9bn international airport in the next few days, Portuguese newspaper CM reports.

Ground could break by the end of the year, infrastructure minister Miguel Pinto Luz said.

He said negotiations would “define all the conditions for the new Lisbon airport”.

The plan, which has been under discussion for decades, is to build an airport to serve the centre and south of Portugal.

When all stages are finished in 2050, the airport may have a capacity of 100 million, putting it in the first division of airports around the world.

At that point, Lisbon’s existing Humberto Delgado airport would be dismantled.

The government announced two weeks ago that the site for the work is to be a military firing range at Alcochete, across the bay of the Tagus from Lisbon.

The airport’s first €9bn phase is expected to be complete in 2034.

Vinci will build it and operate it through its ANA Aeroportos subsidiary, which also manages Delgado airport.