The AGV (Automotrice Grande Vitesse) train will travel at up to 360km/h (224mph), powered by motors placed under each carriage, the company says.

The absence of locomotives at either end allows it to carry more passengers.

Alstom compares the AGV - successor to the TGV - to the world's largest passenger plane, the Airbus A380, in terms of importance and innovation.

"That we are here today is testimony to the courage of Alstom, because during its worst period it decided not to sacrifice its research and development," Mr Sarkozy said in front of the new train at Alstom's rail test centre in La Rochelle, western France.

In 2004, Mr Sarkozy, then finance minister, intervened to save Alstom by partially privatising the company and blocking a takeover by Germany's Siemens which wanted to dismantle the French giant.

"We need to entrench a simple message in people's minds: industry is not over, industry is essential for the economy of a rich nation as much as an emerging nation," Mr Sarkozy said at the launch.

World record

The new AGV trains are set to travel 1,000km (600 miles) in three hours, which is "a new stage in the competition with the airlines", said Alstom's Executive Chairman, Patrick Kron, at the ceremony.

With a motor under each carriage, the AGV - which translates as "high-speed railcar" - is unlike the TGV, which has motors only at the back and front.

It was also built using Alstom's own funds rather than as a joint venture with the state rail firm SNCF as the TGV was.

The TGV's maximum speed currently is 320km/h. But a modified TGV achieved a world rail speed record for a train on conventional rails last April, reaching 574.8km/h.

The AGV's new motors are more energy-efficient and the innovative multiple-unit design allows more passenger space, Alstom says.

It also reduces maintenance costs, the company says.

The Italian operator NTV has already bought 25 of the AGV trains, and will run them on the Italian high-speed network at a speed of 300km/h in 2011.