Rupert Murdoch’s News Corp said on Wednesday its Sky Italia unit had filed a lawsuit against two of Silvio Berlusconi’s media companies for anti-competitive practices in Italy, adding to a growing commercial battle between the two media tycoons.

Sky Italia, News Corp’s Italian satellite pay-television division, is suing RTI, the company that operates the TV channels of Mr Berlusconi’s Mediaset media empire, and Publitalia, Mediaset’s advertising division, for refusing to accept advertising from Sky Italia.