Wolff, Mercedes-Benz and Ineos currently each hold 33% stakes.
Mercedes said it would be making no comment on the reports but added "the governance of the team will remain unchanged, and all three partners are fully committed to the ongoing success of Mercedes-Benz in Formula One."
The reports indicated the Austrian -- who serves as team principal as well as head of Mercedes motorsport -- planned to bring an outside investor into the holding company that owns his stake.
The FT quoted a person with knowledge of the matter saying that the unidentified investor would end up taking a stake of about 5% in the team, with Wolff remaining in his roles.
Sportico spoke of a "mid-single-digit stake".
Mercedes won eight constructors' titles in a row from 2014 to 2021 and are second in the 2025 standings after 21 of 24 rounds.
McLaren, who use Mercedes engines, have clinched the constructors' crown for the second year in a row and look set to add the drivers' title as well.
Bahrain's Mumtalakat and Abu Dhabi's CYVN Holdings took full ownership of McLaren Racing last September in a deal one informed source said at the time valued the champions at $5 billion.