Businessman Denis O'Brien bought 5 per cent of Independent News & Media today, increasing his stake to 27 per cent, a source close to the company said.

Mr O'Brien, who was already the largest shareholder, consolidated his control over the company last month when  Gavin O'Reilly stepped down as chief executive.

The source, who declined to be identified because he was not authorised to speak to the media, said Mr O'Brien bought "around 5 per cent" of the company.

Thomson Reuters data showed 32.7 million shares were sold to an investor at 11.01am, representing 5.95 per cent of the company's 550 million outstanding shares.

Shares in INM were up 15 per cent on the Iseq as news of the purchase spread.

A spokesman for Mr O'Brien declined to comment.

An Independent News & Media spokesman said the company had not been informed of the identity of the purchaser.

Mr O'Reilly's departure brought to an end his family's 30-year control of Ireland's largest media company and ended years of squabbling between Mr O'Brien and the O'Reillys.

Reuters