Sauber will become the Audi works team from 2026 with the two parties entering a strategic partnership.
The German manufacturer announced its entry into F1 as a power unit manufacturer at the Belgian Grand Prix weekend, becoming the first of two prospective Volkswagen Group entries to the sport.
But whilst Porsche's entry has failed to materialise, Audi and Sauber have now confirmed rumours of a tie-up that were heightened by the news Alfa Romeo would end its partnership with the Swiss outfit at the end of next season.
The move will 'guarantee the long-term future' for Sauber, which at numerous points before being partnered with Alfa Romeo was seemingly doomed following a lack of cash injection.
Audi's partnership ensures Sauber's first works-team entry since splitting with BMW at the end of 2009, with the German marque also planning to acquire a stake in the team.
“Audi is the best strategic partner for the Sauber Group," said Sauber chairman, Finn Rausing.
"It is clear that we share values and a vision, and we look forward to achieving
our common goals in a strong and successful partnership.”
Team principal Fred Vasseur added: “The partnership between Audi AG and Sauber Motorsport is a key step for our team as we continue to make progress towards the front of the grid.
"To become Audi’s official works team is not only an honour and a great responsibility: it’s the best option for the future and we are fully confident we can help Audi achieve the objectives they have set for their journey in Formula 1.”
Sauber will continue to compete in 2024 and 2025 with current power unit provider Ferrari, "honouring its existing partnership that enabled the team to make major steps forward in competitiveness and stability."
Audi AG board member Oliver Hoffmann, who is responsible for the F1 programme, said: “We are delighted to have gained such an experienced and competent partner for our ambitious Formula 1 project.
"We already know the Sauber Group with its state-of-the-art facility and experienced team from previous collaborations and are convinced that together we will form a strong team.”