Mediaset is Italy's largest broadcasting company. The company owns three historical channels: Canale 5, Italia 1 and Rete4 plus thematic channels Boing, Iris, La5, Mediaset Extra and Italia 2. Altogether, Mediaset channels closed 2017 with a 31.8% audience share in the prime time slot, a 31.5% share over the 24-hour period and a 31.7% share of daytime viewers. Mediaset also operates a pay-DTT platform (c.1.8m subscribers). It owns a 51.63% stake in Mediaset España, Spain's co-leading free-to-air TV broadcaster and a 42.03% stake in EI Towers, a tower business. Silvio Berlusconi's holding company Fininvest is Mediaset's main shareholder.