Portugal in talks about F1 race at Algarve
The Portuguese Grand Prix last took place in 1996, with Estoril hosting 13 successive F1 grands prix from 1984.
Work was completed on the 100,000-capacity 2.9-mile circuit Algarve International Circuit, 15 minutes drive from Portimao, in 2008.
It is believed the Portuguese government asked Algarve circuit bosses to explore the possibility of bringing F1 back to the European country.
Talks have taken place between the Algarve track and F1's new owners, but discussions are at an early stage.
The venue believes it is ready to host F1, with the necessary infrastructure in place in the local area.
But it understands it is a competitive market, with France returning to the calendar after a 10-year hiatus, with a race at Paul Ricard in 2018, along with Germany.
However, the Portuguese economy is bouncing back after a tough period and the government is believed to be in a position to supply funds - providing the fee is sensible.
It comes at a time when F1 commercial boss Sean Bratches and sporting chief Ross Brawn are formulating next year's calendar.
Brawn is keen for quality over quantity, while Bratches has said the new owners are being "proactive" in targeting markets that it wants to take F1 with a view of expanding the calendar beyond 21 races from 2019.
Those markets have been outlined as Europe, Asia and North and Latin America.
The Algarve circuit has never hosted a Formula 1 grand prix, but has previously welcomed F1 cars.
It hosted three tests - one in December 2008 and two in January 2009 - with Ferrari, McLaren, Toyota, Renault, Toro Rosso and Williams all running at some point.
It was also the venue for Lando Norris' test of a McLaren F1 last week as part of his prize for winning the 2016 McLaren Autosport BRDC Award.
Previously, the track hosted a round of the World Superbike Championship, A1GP and the FIA GT Championship.