Audi has chosen Swiss-based Sauber as the team with which it will enter Formula 1 from the 2026 season.
In a long-expected deal, the German car giant is set to buy a stake in the Swiss team, making it Audi's factory entrant.
Audi is designing an engine for its entry, which coincides with the introduction of F1's new power-unit regulations for 2026.
Sauber will race in 2024 and 2025 with its current engine supplier, Ferrari.
Alfa Romeo is ending its branding of the team after 2023.
Finn Rausing, chairman of Sauber's board of directors, said: "Audi is the best strategic partner for the Sauber Group.
"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."
Oliver Hoffmann, the Audi board member responsible for its 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."
Audi is a part of the Volkswagen Group, which had planned to enter F1 in 2026 with Porsche as well.
However, Porsche's plans to team up with Red Bull as an engine partner fell through after the team refused to give up its independence.
World governing body the FIA said in a statement last week that Porsche was still in talks with F1 teams over a partnership.
However, it remains to be seen how that would work, as Porsche does not yet have an engine - it had planned to partner with Red Bull's new powertrains division.
-BBC