News Corp, the global media company, has signed a new five-year, $25m contract with Roger Ailes, the head of its television group.

The contract also calls for an annual bonus of at least $1m, and includes a grant of 330,000 restricted stock units, according to a filing with the Securities and Exchange Commission.

Mr Ailes, an advisor to several Republican presidents, was hired in 1996 by Rupert Murdoch, News Corp?s chairman, and soon brought the fledgling Fox News Channel to ratings dominance over its more established 24-hour news rival, CNN.

His portfolio was expanded in August to include oversight of the company?s 35 broadcast television stations, its website and its syndication operation, following the surprise resignation of Mr Murdoch?s son, Lachlan. Among other things, Mr Ailes is known as a keen judge of on-air talent, turning Bill O?Reilly and Shepard Smith into stars.

The new contract would appear to secure his services at a time when the company is poised to embark on another ambitious project: the launch of Fox Business, a cable business channel. Some analysts and investors question the appetite for such an offering following the collapse of stock market bubble in 2001 and the subsequent failure of CNNfn and setbacks at CNBC.

Yet Mr Murdoch is understood to be intent on the network, and News Corp is currently in discussions with cable operators to ensure distribution for the new network. One crucial milestone will be sealing an agreement with Time Warner Cable, CNN?s parent company, which controls the vital Manhattan market.