France’s market regulatory body, AMF, ruled on Friday that Bollore Group’s control of Vivendi last year as the media conglomerate was maneuvering to split into four companies, triggered a requirement that Bollore Group make a buyout offer for Vivendi, prior to the company’s split-up. Word of the ruling was reported by Reuters . 

The decision marked an about face by the AMF which had ruled last year that a buyout offer was not required by Bollore before Vivendi proceeded with its split into four companies, including Havas, Canal+ Group, Louis Hachette Group and Vivendi (which retained assets including videogame publisher GameLoft, and minority stakes in companies such as Universal Music Group and other firms).  

The reversal followed a decision by a French appeals court earlier this year that AMF had initially erred in determining that a buyout was not required. The court vacated that decision and ordered AMF to reconsider the matter.  

The case isn’t settled yet as France’s Supreme Court is hearing appeals on the matter by Vivendi and Bollore. 

While last week’s ruling is unlikely to undo Vivendi’s four-company split, it could force Bollore Group to make a buyout offer for shares of the surviving Vivendi entity that it does not own, depending on the outcome of the appeal to the Supreme Court.

Shares in Vivendi are up 19% over the last five days of trading.