Utilize the input text as a context reference, choose the right relationship between 'Bolloré' and 'Vivendi' from the options.
Options: position held, employer, owner of, platform

PARIS—French billionaire and Vivendi SA chairman Vincent Bolloré ousted the longtime chief of Canal Plus on Thursday, further tightening his grip over the Vivendi-owned pay-TV group amid falling subscriber numbers.
owner of