BERLIN, April 12 (Reuters) - ProSiebenSat.1's top investor has asked for individual votes on executive and supervisory board members at next month's shareholder meeting, potentially complicating the German media group's attempts to get its nominees approved.

MediaForEurope (MFE), controlled by the family of former Italian Prime Minister Silvio Berlusconi and previously known as Mediaset, holds a voting stake of more than 25% in ProSieben and has had at times tense relations with the German group.

MFE, which also operates commercial broadcasters in Italy and in Spain, invested in ProSieben in 2019 as part of a cross-border strategy to tackle challenges posed by streaming giants and online advertising platforms.

But ProSieben responded coolly to its top investors' overtures, pursuing a standalone path.

In December, ProSieben did not inform MFE in advance about an extension to its CEO's contract and its proposed nominees for the renewal of its supervisory board.

The move triggered a squabble over governance, with MFE reserving the right to present rival candidates at the AGM by April 20.

Last month, ProSieben said MFE had rejected a seat on the supervisory board, suggesting no compromise had been reached.

"Instead of a uniform vote as proposed by the company, MFE intends to enable each shareholder to assess and to approve the work of ProSiebenSat.1's executive board and supervisory board members individually," MFE said in a statement.

It said it made a formal request for the individual votes to ProSieben on April 4 in accordance with German stock corporation law.

ProSieben said it would process the request according to the German legal rules. (Reporting by Klaus Lauer and Alexander Huebner, Writing by Elvira Pollina Editing by Madeline Chambers and Mark Potter)