Alfa Romeo have announced they will end their title sponsorship with Sauber at the end of the 2023 Formula One campaign.
The Italian manufacturers returned to the F1 paddock in 2018 with a technical and commercial partnership, with an extension in 2021 including 'multi-year assessments'.
Last month, Alfa Romeo opted to remain on the grid for the 2023 season but have now announced it will be their last.
In a statement, they said: "Since the economic and industrial turnaround of the brand will be achieved in 2022, Alfa Romeo will now evaluate among the many opportunities on the table, and decide which will be the best one to sustain the long term strategy and the positioning of the brand."
Alfa Romeo's exit paves the way for Audi's introduction, with confirmation on Friday they would join in 2026 as an engine supplier – though the wider expectation is that they will bring the four rings to the paddock as a team, with reports indicating an agreement with Sauber is 75 per cent complete.
Sauber's future on the grid in the period between the end of the sponsorship with Alfa Romeo and any potential deal with Audi is unclear, however, though they have previously raced under their own name.
Prior to the start of the agreement with Alfa Romeo, Sauber raced under their own name from 2011, and have extensive history in F1 from 1993 including partnerships with BMW, Mercedes and Red Bull.
Alfa Romeo currently sit sixth in the constructors' championship with 51 points, having finished ninth with just 13 points in 2021.