Most of the moguls who run the world's largest media empires are American. Many of them are nearing retirement age. For some, their best years seem behind them.

Not Jean-Marie Messier. The 44 year-old French chairman of Vivendi Universal has emerged as the world's most dynamic media and communications executive.

Mr Messier, a former investment banker schooled in the ways of French politics, has knitted together a company rooted in the Paris establishment with one of North America's best-known stable of entertainment assets.

With Vivendi's $34bn acquisition of Seagram, the Canadian drinks company which owned the Universal movies and music businesses, Mr Messier created last year one of the world's largest media and communications companies.

Since then, he has bolted on several other businesses. This year, Vivendi Universal has bought Houghton Mifflin, the Boston-based educational publisher. It has created an alliance with Sony to deliver music over the internet.

The global patchwork of businesses has pieces missing.

Vivendi Universal has distribution in Europe, thanks to Canal Plus, the pay-TV operator, and its SFR mobile phone business. But it still lacks access to a distribution network - a TV broadcasting business, a satellite TV operation or a cable infrastructure - in the world's wealthiest media market, the US.

Mr Messier has championed an expensive foray into internet content, ploughing money into Vizzavi, a joint venture with mobile giant, Vodafone. Vizzavi is seen as a portal for all devices: personal computer, television, hand-held device or mobile phone.

The question Mr Messier and Vizzavi still have to answer is whether it can lure customers away from services, such as AOL and Yahoo!, which seem to offer the same and more.

Mr Messier has said he is focused on distribution. He has said that he has no plans for a big acquisition to get customer access. Instead, he says, he is looking at alliances and joint ventures to get into more homes. (That said, Mr Messier has told investors before that he has no M&A plans, only to announce the multi-billion dollar purchase of Houghton Mifflin a fortnight later.)

Vivendi Universal has an indirect route to the American customer: USA Networks, an entertainment and e-commerce business controlled by Barry Diller. Vivendi Universal has a substantial minority stake in USA Networks, but has contractual rights to increase that shareholding to more than 50 per cent.

Mr Diller is a would-be buyer of NBC, if the US broadcasting network owned by General Electric ever came up for sale. If it did, USA Networks could prove to be Vivendi Universal's route to becoming a tier-one media company, not on a global basis but by the domestic standards of US media giants.

In the US, Vivendi Universal boasts Universal Music, the world's biggest music group, and Universal Studios, which has had an enviable record churning out such hits as The Mummy Returns and Gladiator.

The company has continued to generate creative products even through a merger which could have created real strains. It was a French takeover of an American company of artistic types. Many people could have walked out the door or stopped working.

But Mr Messier, who has set the company on course to hit demanding financial targets, appears to have presided over a remarkably rapid integration.

The business has hit its double digit cash flow targets. It has held on to most of its main executives. Edgar Bronfman Jr, the scion of the Bronfman family which controlled Seagram, relinquished his executive responsibilities overseeing the music group at the beginning of December. However, he was not seen as central to the leadership of the company after Mr Messier took control of the combined entity a year ago.

Mr Messier, a big personality with what seems to be an unhesitating self-confidence, recently put down the successful combination of Vivendi Universal to the combined efforts of French and North American executive teams, including Mr Bronfman.

"The integration has been more of a success, both in depth and in time, than we could have expected," Mr Messier said.