(FORTUNE Magazine) – If a band of evil aliens wanted to destroy the Internet, they could have triumphed in one swift stroke--by zapping San Jose's Fairmont Hotel on a brilliant day in early July. Inside, one of the world's biggest Web investors, Masayoshi Son of Japan's Softbank, sipped ice water and swapped e-news with E*Trade chief Christos Cotsakos, while an ebullient Chris Larsen, fresh from guiding E*Loan to a stirring IPO, swept from table to table collecting kudos from the CEOs of WebMD, InsWeb, and Concentric. Just when it seemed the Fairmont had maxed out on cyber-royalty, Yahoo CEO Tim Koogle and co-founder Jerry Yang pulled up. Thank heavens the aliens were napping!

For once, the Cotsakoses and Yangs weren't the stars. The elite had gathered to court a team from Rupert Murdoch's News Corp. and a moon-faced Frenchman named Jean-Marie Messier, CEO of Vivendi, until recently a rusty provincial water company. Masayoshi Son--a big investor in all the companies present--wants Messier to take the first crack at forming exclusive partnerships in Continental Europe with Web companies in his stable. He's offering the same deal to Murdoch for Britain. Son arranged the beauty contest at the Fairmont so that Messier and the Murdoch crowd could take their pick of partners. With the elan of Louis XIV anointing ministers, Messier announced his favorites, among them E*Trade, E*Loan, and WebMD.

Messier, a former government official who played an active role in France's privatization drive in the 1980s, has plenty to offer the masters of the Web. He has won a reputation as one of the brightest of Europe's new breed of entrepreneurial musketeers--and has the record to back it up. In three years as CEO, he has taken Vivendi (1998 sales: $37 billion) from a midget in communications to a titan standing shoulder to shoulder with Bertelsmann of Germany and News Corp., one of Britain's biggest players. Vivendi shares have risen sharply, and its market cap has multiplied sevenfold to $43 billion. As controlling shareholder of Canal Plus, which has 13 million viewers, Vivendi is the biggest pay-TV operator in Europe. It is also the largest private mobile phone company in France and one of the largest in Europe. And to complete the circle of media holdings, Messier is bringing his own content to the Net with big deals like this year's purchase of California's Cendant Software, now renamed Havas Interactive, the world's biggest maker of PC games.

Messier is not stopping to catch his breath. Indeed, he has a dream--to knit together the PC, the mobile phone, and the TV screen so that customers can buy an InsWeb auto policy or shares via E*Trade over all three. It is this grand vision that has the e-elite fawning. So far, Vivendi, which has been an early champion of this new technology, is beating out the competition in Europe. It also has a lead on rivals in the U.S., where the hodgepodge of cell phone standards is a major barrier to uniting services into a seamless, well, web. In Europe, Messier says, the technology and the regulatory structure are there--and he thinks he can get the job done by 2002. The idea is catnip to Web moguls. Such integration would allow them to multiply their audience by providing the same advertising and service over cell phones and pay TV they can now offer only on PCs.

It's fitting that Messier and the Murdoch team shared the place of honor in San Jose. In fact, this relative upstart from France is pressuring the Australian-American magnate into becoming his partner in a venture that could revolutionize the European communications market. And he did it with a flair that would have made Richelieu proud. Here's what happened.

In February, Murdoch courted Messier with a proposal to merge BSkyB with Canal Plus to create a pan-European pay-TV empire of 20 million viewers. Messier loved the idea but demanded management control of the proposed partnership. Murdoch--surprise, surprise--also insisted on running the show. Messier demurred, then went through the back door. In March, Vivendi bought a 17% stake in BSkyB as part of a merger with filmmaker Pathe. In late July it purchased another 7.5% from British media companies Pearson and Granada. With a 24.5% holding, Messier can now veto just about any big decision Murdoch makes.

Messier says he's not seeking a merger. But the partnership he does covet is almost as powerful. Right after he first invested in BSkyB, Messier proposed to Murdoch that the two networks cooperate in creating the next generation of digital TV technology. Today BSkyB and Vivendi work on incompatible media "Web boxes," the set-top consoles that will allow viewers to buy stocks or choose hotel rooms over the Web. Messier suggested to Murdoch that the two companies pool their efforts to develop a single box combining the best technology from both camps. That would give manufacturers economies of scale and allow Canal Plus and BSkyB to offer their combined customer base to Internet service providers. "That way, the Internet companies would have to pay higher prices to get access to all those customers," says Messier.

Murdoch agreed to explore the idea, a spirit of cooperation that Messier attributes to Vivendi's new power as a shareholder. In short, at BSkyB, it's Messier who holds the whip hand. If Murdoch balks, Messier can systematically frustrate his plans. "We intend to be a very active shareholder," he declares.

Messier is considered a business rebel in France--a modern-day Robespierre bent on overthrowing the ancien regime. But his early resume is so traditional it could be stamped with the fleur-de-lis. Son of an accountant from Grenoble, Messier graduated from both the Ecole Polytechnique, training ground for the business elite, and the Ecole Nationale d'Administration, the legendary academy for civil servants. Although "ENArques" continue to run vast swaths of France, Messier is dismissive of the school: "You learned nothing about the real world outside of France."

Next he joined the prestigious corps at the Treasury responsible for auditing state-owned companies--and began bucking the system. Unlike many of his colleagues, this auditor actually audited. He unearthed lots of fishy practices and relished brandishing his work in front of his stunned bosses. Heads rolled after his findings of dubious practices at a software arm of CEA, the French atomic energy producer. "The people I examined didn't like me," he brags.

In 1986, at the age of 29, Messier began advising the Ministry of Finance on privatization programs. But even selloffs could not kill the old system. As the privatizations wound down, the Finance Minister, following a hallowed tradition, prepared to distribute top posts in remaining state-owned companies to his young lieutenants. Messier refused all offers. "That was the problem with French management," he says. "The big jobs went to bureaucrats who weren't trained for them."

As Messier saw it, great managers needed to know how to make transatlantic deals. So in 1988 he joined investment bank Lazard Freres as the youngest partner in its history. Messier became the man French companies came to see when they wanted to expand into the U.S. But Messier wanted to combine dealmaking with kick-the-tires operating skills. So he persuaded the Lazard partners to hand him money to found one of Europe's early LBO funds. He spent his weekends in grimy industrial cities in France and Germany, recruiting CEOs, preparing budgets, and analyzing receivables for manufacturers of valves, franking machines, and wallpaper. The fund prospered, and Messier says the experience taught him the most important lesson in business: Treat the company's assets like your own.

Then in the early 1990s, Messier seized the opportunity he'd been training for, in the unlikely guise of Cie. Generale des Eaux, the most hidebound and provincial of all French industrial landmarks. Founded in 1853 to bring potable water to Lyon, CGE had drifted into apartment buildings, theme parks, catering, and travel agencies. When the real estate portfolio hemorrhaged cash, CGE borrowed recklessly to support its water business, which was doing well in France but had barely wet its feet abroad: Only 20% of sales were overseas. Autocratic Chairman Guy Dejouany, then in his 70s, realized CGE had to change to survive. Enter Messier. Although his initial brief was to sell real estate, Messier had much bigger ideas. He saw the mess at CGE as his big chance to transform an old-line company by pursuing newly deregulated, high-growth markets. Enthralled by this vision for rebuilding CGE, Dejouany made Messier his dauphin in 1994. Two years later the young man was crowned CEO.

Messier's strategy was twofold. First, sell CGE's water-supply expertise overseas. Second, "dig out the truffles!" That meant concentrating on two choice items buried in CGE's sprawling portfolio and selling almost everything else. One was mobile phones, an area CGE was neglecting because it looked like a market strictly for rich people; France Telecom sold mobile phones for about $800. Messier strove to make them an inexpensive, mass-market item. He offered splashy, U.S.-style promotions, like free calls on weekends and evenings. When the elephantine FT bristled at cutting prices, CGE didn't, grabbing a bigger share of an explosively growing market. Vivendi's telecom arm, Cegetel, part owned by Mannesmann and SBC of the U.S., became one of the fastest-growing companies in French history. Today it boasts $5 billion in sales and a market share of 42%, second to FT.

The other hidden gem was pay TV. When Messier arrived at CGE it held less than 30% of Canal Plus, its only media holding. Realizing that a controlling interest would make CGE a partner of choice for U.S. or British media companies entering Continental Europe, Messier relentlessly scooped up shares, raising CGE's ownership to a decisive 49%. And last year Messier bought one of France's biggest publishing houses, Havas. Messier has totally recast Havas, purveyor of the famed Larousse dictionary and other tres French titles, as a multimedia player that sells videogames and publishes professional journals on the Internet.

In the wake of these transactions, the CGE name began to look faintly silly, since almost half the company was now media related. Typically, Messier ignored the advice of his ad agencies, who recommended a strong-looking acronym featuring the letter x. In 1997 he chose Vivendi, a word derived from the Latin verb "to live": "I wanted a European name, not a French name. And Vivendi sounds so musical."

Messier adores the high profile of a media mogul. Unlike most French bosses, he has never met a microphone he didn't like. Just after becoming CEO, Messier organized a kind of town meeting with 5,000 employees under the age of 30, striding into the cavernous arena to blaring rock music. He is not modest. A magazine once asked him, If you could be a plant, what species would you choose? "I would be--a forest!" Messier riposted. But as a manager, Messier prefers Cartesian logic to emotional outbursts. "He never looks for fights," says a former colleague. "He arranges things like a Renaissance cardinal."

Despite his disdain for the French business establishment, Messier is a traditionalist when it comes to the good life a la francaise. He is a proud member of the Club of 100, a group of Frenchmen who adore Gallic cuisine. To be admitted, Messier had to pass a test in which members questioned him on what wines to serve with certain cheeses, or how to harmonize courses without making the flavors clash. "He passed brilliantly," says fellow member Jean-Louis Beffa, CEO of glassmaker Saint-Gobain. Messier even installed a gourmet dining room at his Paris headquarters, headed by chef Gilles Mery, a protege of the famed Joel Robuchon. Messier waxes passionate describing the way Mery cooks his favorite dish, a grilled hen from Burgundy, served with a 1982 Ducru-Beaucaillou, a red Bordeaux.

Messier's favorite drinks are a good Bordeaux--and water. But perhaps he has to say that, since water remains one of Vivendi's two core businesses and brings in more revenue than all the glamorous media action. Still, with high-concept communications plans in his pocket, why does Messier bother to keep such a distinctly old industry like water? The reasons are classic Messier. As a growth industry, water is a fair match for media--and Vivendi happens to be very good at it, supplying thousands of towns in France, a country that knows its water. As in communications, Messier is jumping on a churning market--the giant U.S. water business--that is in the midst of being transformed by deregulation.

Pressed for cash and by demand for performance, thousands of American cities are asking private companies to build new water plants for them, or to upgrade and run their existing facilities. Vivendi wants a big piece of that action. But its efforts to plunge into the U.S. market in the early 1990s were feeble, partly because its French management team wasn't adept at captivating rough-hewn city councilmen. So Messier decided to go local in a big way, acquiring U.S. Filter, the largest maker of water-treatment equipment in America, for $6.2 billion. It is the biggest-ever French acquisition of an American company and gives Vivendi a strong position in America. U.S. Filter supplies 1,500 municipalities, from Franklin, Ohio, to Arvin, Calif.

But can Messier manage such totally different businesses as water and communications, with not a drop of synergy between them? "Being in both jet engines and finance doesn't bother Jack Welch," he responds modestly.

Messier has proved skilled at assembling a more coherent business from a senseless jumble of assets. Now he must prove that he can make the parts work together. While he's trying, rivals will mimic his strategy of collecting subscribers for the Internet explosion. But for now, Messier is way ahead of the crowd. And he'll be tough to outfox. Just ask Rupert.

REPORTER ASSOCIATE Deirdre P. Lanning