The move comes at time of a deepening crisis at Germany's ProSiebenSat.1 and increases pressure on the German group's chief executive, Max Conze, who has shown little enthusiasm for a closer tie-up with Mediaset.

ProSiebenSat.1's share price has been hovering at its lowest levels in a decade in recent weeks, also hit by the spreading coronavirus crisis in Europe.

In a statement on Monday, Mediaset's Spanish unit Mediaset Espana said it had secured a further 4.25% stake in ProSiebenSat.1 for around 61 million euros, raising its share in the German company to 9.75%.

This adds to the 9.6% already owned by Milan-based Mediaset, which is controlled by the family of former Italian Prime Minister Silvio Berlusconi.

The overall stake corresponds to voting rights for 20.1%, Mediaset said in a separate statement.

Earlier this month, Mediaset said it was considering its options for its investment in ProSiebenSat.1, adding the need for the European TV industry to consolidate was greater than ever.

Finance chief Marco Giordani said at the time that Mediaset was awaiting a ProSieben strategy update next month to decide whether "to stay, to leave or to increase" its stake.

Mediaset built the stake last year to push its broader agenda of uniting broadcasters under a European holding company it is setting up.

ProSieben's Conze has, for his part, pushed back against the idea of a merger while welcoming Mediaset's investment as a vote of confidence in his strategy and pushing to deepen cooperation in areas such as video streaming.

German media have speculated that Mediaset could team up with Czech investor Daniel Kretinsky, who controls a 10% stake in ProSieben, to oust supervisory board chairman Werner Brandt and CEO Conze at this year's annual shareholders meeting.

Several top executives have left ProSieben of late as Conze has struggled to turn around the business, with Deputy CEO Conrad Albert the most recent to exit after slamming what he called a ?boardroom soap opera? at the German broadcaster.

ProSieben declined to comment on Mediaset's latest move. It said in a separate statement that Conze and CFO Rainer Beaujean would share Albert's duties with immediate effect. Albert is due to leave the company on April 30.

(Reporting by Elvira Pollina and Agnieszka Flak; Additional reporting by Douglas Busvine; editing by Barbara Lewis and Mark Potter)