The Paris media elite broke open the champagne on Monday night and partied away within sight of the Eiffel Tower after the boards of Canal Plus, Vivendi and eventually Seagram all agreed to a three-way merger between their companies in a $40.2bn deal including debt that creates Europe's first truly global entertainment conglomerate.

More precise details of this new company, to be known as Vivendi Universal, will be unveiled on Tuesday morning, first at an analysts briefing, and then at a scheduled press conference in Paris attended by the three key executives set to run the combine: Vivendi chairman Jean-Marie Messier, Canal Plus chairman Pierre Lescure and Seagram chief executive Edgar Bronfman Jr.

But even before news of Seagram's eventual blessing of the marriage leaked out at around 7pm local time in New York, the partying had begun on the streets of the French capital.

With Messier leading the party in his shirt sleeves and Lescure chewing happily on a big Havana it was clear Monday night that the deal was already in the bag by then even though they were there ostensibly to celebrate the launch of Vizzavi - an internet portal that looks to play a pivotal part in the Vivendi-Universal collosus.

Fittingly, for an occasion marking Europe's first real attempt to redress the global playing field that has tilted so far towards Hollywood, the French pulled out all the stops, rolling out elephants, camels and the obligatory dancing girls.

But now comes the hard part. The new management behind Vivendi Universal will need to persuade sceptics within financial circles on both sides of the Atlantic that the premium price being paid for Seagram will create a company greater than the sum of its parts. Already, the company is having to spin off units, either to satisfy French law in the case of Canal Plus' local broadcasting and production arms, or in order to help pay for the merger in the case of Seagram's drinks business.

There are also several areas of potential overlap, particularly on the film side. In the UK, for example, the deal means that Vivendi Universal has a stake in both UGC Cinemas and the UCI chain. And then there is the question of parallel film distribution and international sales apparatuses, not to mention dual production ambitions. StudioCanal chairman Vincent Grimond has already insisted, in an interview with Le Monde, that his fast-growing film operation will remain separate from Universal.

Furthermore, the deal may well face a protracted review from the European Commission. Regulators from this same body opened a four-month probe on Monday into the AOL/Time Warner deal, citing concerns about vertical integration particularly in the areas of internet music distribution. Those issues are just as germane to Vizzavi, a venture which would love to draw on Vivendi Universal's music catalogue, the world's largest.

Vizzavi is the joint-venture brainchild of French media and utilities giant Vivendi, its 49% subsidiary Canal Plus and Vodafone Airtouch, soon to be the world's largest mobile phone group.

As its original name Multi Access Portal suggested before giving way to marketing glitz and corrupted rendition of the French phrase meaning "face-to-face", Vizzavi is intended to deliver content to a range of digital devices; whether they are fixed, mobile and wireless phones, or else desktop, palmtop or some form of television computer.

But already, even as Vizzavi job ads are being plastered all over European newspapers, the venture is under anti-trust investigation by the European Commission.

At the moment Vizzavi has only a few million potential customers and 200 unique services within its so-called "walled garden" of customer offerings. But in time, Vizzavi is expected to reach a massive 80 million paying subscribers and to add on hundreds of third party functions.

When Messier boasted at last year's MIP-COM convention that he headed a group with 30 million subscribers he was implying that analysts should not just count Canal Plus' 10 million or so pay-TV watchers scattered over Europe and North Africa, but also add in all his subscribers to Cegetel, France's second largest mobile phone network. By teaming up with Vodafone he has now added nearly three times as many clients and gained a subscriber base that extends around the globe.

Like all portals, however, Vizzavi is crying out for content and perhaps this is why the Bronfman family that have ruled Seagram for three generations may have finally decided to trade in their family empire for an 8% share in Vivendi Universal. Vizzavi may finally unlock all the latent value in Universal's stockpile of existing video and audio copyrights.

In addition, if Vizzavi can be demonstrated to reach new customers and add value for content owners, it may be the key element that decides whether News Corp remains at loggerheads with Vivendi or becomes a powerful ally.

Vivendi and News Corp owner Rupert Murdoch are currently skirmishing over Vivendi's 21% stake in BSkyB. But before even this squabble broke out, there were quarrels over set-top decoder technology and sports rights for pay-TV. Settling those scores as part of a deal that would add content from 20th Century Fox to the Vizzavi mix would make Vivendi Universal a player able to stand up to any other entertainment grouping on the planet.

Colin Brown IN NEW YORK also contributed to this report