By Elvira Pollina and Valentina Za

MILAN (Reuters) - Amber Capital will back a strategy shift at ProSiebenSat.1 put forward by the German broadcaster's top investor MFE-MediaForEurope at a shareholder vote later this month, a senior executive at the activist fund told Reuters.

MFE, which holds nearly 30% of ProSieben, is proposing splitting the group's e-commerce and dating assets from its core TV operations, in an effort to speed up a long-awaited relaunch of the Bavarian broadcaster.

Controlled by the family of the late Italian Prime Minister Silvio Berlusconi, MFE is Italy's biggest commercial broadcaster and an advocate of pan-European consolidation in the sector.

MFE is seeking to garner shareholder support for its proposal, which has been rejected by the Munich-based company, ahead of a vote on it at ProSieben's annual general meeting on April 30.

"We will support MFE's proposal at the AGM as we believe it is the only way to create value for shareholders," Joseph Oughourlian, chairman and founder of Amber Capital told Reuters.

Amber is a top 15 shareholder in ProSieben with a stake of around 1% held in part through derivative contracts. It is the first significant investor to comment publicly about MFE's proposal.

Oughourlian did not rule out Amber could buy more ProSieben shares ahead of the AGM, "depending on the market price".

The activist fund will also vote in favour of other proposals put forward by MFE, including its candidates for the German group's supervisory board, he said.

(Reporting by Elvira Pollina and Valentina Za)