The unquiet American.

Conceptually, the new American Centre is intended to celebrate the intermingling of French and American culture, a creative fusion of Old and New World values underpinned by the tradition of dissipated emigre Americans in Paris, who lived and thrived among the city's rich matrix of cafes, bars, garrets and studios. In reality, it bears a closer resemblance to a cultural trade mission, replete with presidential state opening, grants from the Rockefeller Foundation and a sternly itemised programme of artistic and educational events. The fact that such distinguished Parisian habitues as Stein, Hemingway, Miller, Baker, et al might have found this a trifle institutional, merely reflects the passage of time and attitude. Since the '60s the American Centre has evolved from nebulous beatnik origins in the Boulevard Raspail in Montparnasse to a fully fledged, funded and formalised institution in the newly reconstituted eastern quartier of Bercy.

Bounded by railway tracks to the north and the surging quai de la Rapee along the Seine to the south, the narrow strip of land that originally housed acres of wine warehouses is now being radically transformed to host a benignly interactive mixture of new uses. Unlike the louche commercial sprawl to the west of the city, the aim is to recreate the west of the city, the aim is to recreate the tight, high density, nougaty texture of traditional Parisian streets. The ingredients of this urban potage are admirably varied -- 1200 flats, a commercial centre, creche, offices, two hotels, 3000 parking spaces, a centre for viniculture. But the indisputable architectural focus is Frank Gehry's transatlantic interloper, the new American Centre.

The new building occupies a roughly square plot, defined on its street edge by the rue de Pommard. Mediating between this and an exquisitely manicured new public park to the rear, is an open piazza. On the opposite site of this cobbled space are two execrable examples of production line French hotel design, extruded into a pair of grimly slick colossi. At first sight, Gehry's response is one of calm contextuality. From the rue de Pommard, the new building registers as an apparent continuation of the street facade, with a demurely disciplined arrangement of orthogonal openings punched deep into two stone-clad cubic volumes. As the one facing the piazza reaches first floor level, it splays out slightly over a glazed secondary entrance, as if disturbed by some unseen force.

This subtle dislocation is merely a teasing appetiser, the brief pause before the main punchline is delivered. Around the corner any pretence at Euclidean geometry collapses in an astonishing sequence of abruptly truncated angles, colliding volumes and gravity-defying forms. Like a dangerously deconstructing mansard roof, this fragmented Cubist assemblage marks the main entrance, which is energetically sliced off the corner facing across the Parc de Bercy. Contextually, the intensely sculptural quality is inspired by Gehry's observations of the undulating Parisian roofscape, in particular the monumental Hotel de Ville, endowed with what he calls 'the best cleavage in Paris'. Here, among the voluptuous mansards, Gehry's exuberant compositional sense is splendidly in its element, giving rise to an audacious visual and spatial tension that alternately tantalises and torments.

The castrated corner is the key to the building, the demented fulcrum about which the main volumes rotate. Inside is a sweeping, generous accueil, or public atrium, on two levels where visitors can get their bearings before penetrating the building's hidden mysteries. The space is almost Piranesian in its complexity, overlaid with elevated walkways, balconies, and random protrusions, all infused by a cascading play of light from different sources. The accueil is the link between the two main volumes of the 350-seat theatre on the east side and a cluster of apartments for visiting artists on the northern rue de Pommard facade. With such a great diversity of functions -- theatre, cinema, classrooms, library, dance studio and three exhibition areas, Gehry hopes the accueil will acquire a bustling dynamism similar to that of the Pompidou Centre, with a flow of visitors animating the circulation spaces. He has also striven to dismantle and subvert the building's inherent institutional character. During the humid Parisian summer, the glass doors of the entrance under the zinc-clad awning slide back, dissolving the formal boundaries between inside and out and extending the accueil's informal, inclusive sweep towards the piazza and the park beyond.

From the elevated vantage of the mezzanine the presence, but not the explicit nature, of other spaces is suggested. Blank walls of the cinema and theatre and even the apartments intrude cryptically into the void. Only the dance studio, secreted on the topmost level, is totally concealed. Yet despite the daunting overall scale, the building is studded with provocative incident and detail. The upper level gallery space has public access to a circuitous terrace that meanders around the east side of the roof with breathtaking views over Paris. The theatre foyer on the south elevation is a double-height volume expressed as a sequence of angular glazing hewn jaggedly into the light honey-coloured stone.

The apparently abstract, sculptural massing is the outcome of a studied manipulation and organisation of the various volumes, recalling the imaginative intensity of suburban domestic projects such as the Schnabel House (AR September 1992) but in this case elevated to a grander civic scale. There is also a detectable mood swing; away from Californian languor to a tougher, more boisterous engagement that reflects Gehry's preoccupation with the 'cranky feistiness' of French society. The feistiness also extends to the climate, engendering nervous anticipation for the weathering capabilities of the currently pristine external volumes, but the real test of the Centre's success will be in how extensively it is used in the fluid informal way its architect intended. Compared with the municipal pomposity of many Parisian Grands Projets, it has a refreshing informality and wit, like a good Californian Chardonnay invigorating a jaded palate. A votre sante, Monsieur Gehry.