A major personal sponsor of Mercedes driver Valtteri Bottas has chosen not to renew its deal with the Finn over "weak results" during the 2018 season.
Bottas failed to win a single race last year – although team orders robbed him of at least one win when he was asked to move aside for team-mate Lewis Hamilton in Russia – and he finished a lowly fifth behind both Ferraris and Red Bull's Max Verstappen.
The Wihuri Group, which is owned and chaired by Finnish billionaire Antti Aarnio-Wihuri, has sponsored Bottas' motorsport career for almost 20 years and became a Mercedes sponsor when Bottas joined the team, having moved over from Williams in 2017.
However the Finnish conglomerate has ended its deal with the 29-year-old over his poor form.
"It's been disappointing," Aarnio-Wihuri told Finland's Ilta-Sanomille. "It was not entirely his own fault, some of it was due to the team and technical problems, but I think he was quite weak at the end of the year."
Aarnio-Wihuri admitted that going up against Hamilton was a difficult challenge, but was unimpressed by Bottas' overall result.
"It's a difficult place to be as Hamilton's team-mate, but Valtteri was left behind by many others and was only fifth overall. It was a pretty weak result."
Wihuri also sponsors two young Finnish drivers in Simo Laaksonen and Niko Kari, though the latter's deal is also set to end due to poor form according to Aarnio-Wihuri.
"Supporting Laaksonen will continue. We will not continue with Kari, and the reason for this is little success."
Kari finished the 2018 GP3 season in 17th, but missed the final four races after making the step up to Formula 2 with MP Motorsport, whilst Laaksonen finished 14th with 36 points compared to Kari's six. Neither have confirmed their plans for 2019.