Mexican telecommunications tycoon and billionaire Carlos Slim has bought a 6.4 per cent stake in The New York Times Co., the newspaper publisher.

Mr Slim, the world's second-richest man according to Forbes magazine, is the second prominent investor this year to buy a piece of the US company, which publishes The New York Times, the Boston Globe and smaller daily newspapers.

Asked why he bought the stake, Mr Slim, who has US assets in retail, told reporters in Mexico City, "It's financial," indicating he was not making a strategic move into US media.

He declined to say how much he paid or whether he would increase his stake.

Mr Slim, 68, a son of a Lebanese immigrant, and a rare billionaire who eschews private jets, yachts and other executive trapping, has an estimated net worth of €43 billion, according to Forbes. That is behind only Berkshire Hathaway chief executive officer Warren Buffett's €44 billion.

Telecoms aside, Mr Slim's far-flung business empire includes department stores, a banking group, restaurants and manufacturers of cigarettes, floor tiles and car parts.

His telephone company Telmex, a former state-owned monopoly, has 90 per cent of Mexico's 20-million fixed phone lines. His America Movil is Latin America's biggest mobile phone company with operations from Mexico to Brazil.