Wihuri is a company who enjoys a presence in numerous industries such as packaging, food distribution, construction equipment and jet charter services, has been Bottas' sponsor since his younger years in motorsport.
Antti Aarnio-Wihuri, the owner of the company, and a former racing driver himself, was instrumental in Bottas' transfer from Williams to Mercedes in 2017.
"That's right, we won't go on," he said Ilta-Sanomet. "With regard to the benefit of investing, we decided that it was too expensive. It was disappointing.
"Partly it was not his (Bottas) fault, some of it was due to the team and to technical problems, but I think he was quite weak at the end of the year."
It's now a huge year for Bottas, who has to fight for the right to be a Mercedes driver in 2020, with Esteban Ocon sniffing around.
Bottas was winless in 2018, and the Finn has been told he needs to improve in order to keep driving alongside world champion Lewis Hamilton.