In one vast hall, workers in blue overalls are putting the finishing touches on what would, on a normal train, be a locomotive, except that it houses a spacious conference room with a large table and seven comfortable armchairs.

In an adjacent hall, others are attaching what look like ordinary wheel trucks to a rail car, except that these contain electric motors that will essentially do the locomotive's job of pulling the train.

"We're now turning out a car every one or two days," said Michael Gessner, project manager at the Siemens rail car plant in the Uerdingen suburb of this industrial city. "When we begin the Chinese order, it will be two a day."

Work at the Siemens factory illustrates a coming together of two developments in high-speed passenger train travel: technical breakthroughs in the way the bullet-shaped trains run, and the opening of vast new markets in Eastern Europe and Asia that are combining to give a steady boost to the business.

As countries like Italy and Spain - and emerging markets like China and Russia - open their pocketbooks for huge high-speed rail development, the United States remains on the sidelines, risking to lose out on new technologies for propulsion and vehicle control.

For those who thought railroads were basically 19th-century technology, think again. Thanks to miniaturization, these powerful new trains have motors built into the axles of every second rail car, rather than concentrating the pulling power in the locomotive, as was done in traditional pull-push trains.

The new technology makes the trains lighter and enables the trains to go faster, to brake and accelerate more easily, and to cause less wear on rails and wheels. It also frees up locomotives for up to 20 percent additional seating space. The newer generation of very high-speed trains has other breakthrough features, including so-called eddy current brakes, which employ electromagnetic fields rather than brake disks to slow and stop.

"The carriages are stable and light, and of very high speed," said Frans Lac senior vice president in Alstom's transport division, which will install the new technology in the fourth generation of its TGV.

(The French manufacturer Alstom, like most of the industry, considers high-speed trains those with a top cruising speed of 240 kilometers, or 150 miles, per hour; trains with a top cruising speed 340 kilometers an hour are considered very high speed. The Acela's top speed is about 200 kilometers per hour.)

In November, Siemens landed a $804 million contract to supply 60 sleek-nosed high-speed trains to the Chinese railroads. The order is just one in a 15-year program to upgrade China's rail network, including the introduction of 290-kilometer-an-hour bullet trains. "Up to 2020 they want 12,000 kilometers of high-speed rail," said Dietrich Mir, president of Siemens' trains division.

At about the same time, Siemens signed a preliminary contract for high-speed trains to connect Moscow and St. Petersburg. Like China, Russia, too, has gigantic rail ambitions.

The line may one day continue beyond St. Petersburg to Helsinki and past Moscow to Russian cities like Nizhny Novgorod.

In South Korea, Alstom, the inventor of the train grande vitesse, or TGV, is supplying 300-kilometer-an-hour trains for a five-year, $17 billion project linking the southern city of Busan with the capital, Seoul.

The growth in Asia is giving the small club of high-speed passenger train manufacturers a lift just as Western European governments are watching their budgets more closely. Europe's dense population and geographical features like the Alps make the construction of high-speed lines costly.

Moreover, environmental groups often resist the construction of new train lines, claiming they bring noise and unwanted development and draw money from more urgent needs.

Nonetheless, Spain hopes to have the Madrid-Barcelona link open by 2008; France and Germany are upgrading the line from Paris through Strasbourg and on to the German cities of Stuttgart and Frankfurt for 340-kilometer-an-hour trains.

American industry is largely sitting this one out. While some American companies, like the electromotive division of General Motors and the MotivePower Industries division of the Wabtec Corp., are doing brisk business with Chinese rail operators, their business is mainly freight, while the market for high-speed passenger trains is limited to a small group that has shrunk in recent years through a wave of mergers and acquisitions.

In 2001, Bombardier, the Canadian transport company, acquired Adtranz, a German-based rail equipment maker; at about the same time, Alstom bought Fiat Ferroviaria, Fiat's rail equipment division and the original developer of technology that enables high-speed trains to tilt into curves, much the way a motorcycle can. Within Europe, the three leaders are vying to grab market share with snazzier and ever faster models and new technology.

In Europe, to be sure, the growth of the market is not without its obstacles. Some argue that the cost of high-speed rail is excessive, compared with the operation of no-frills airlines, and that it only indulges a European penchant to go first class whenever possible; others say the environmental damage is too great.

In northeast Italy, near Turin, the site of the next winter Olympics in February, environmental groups are opposing a new high-speed line and tunnel to connect Lyon in France and Turin, arguing they would drag even more industrial traffic into the Alps. The train will cross a valley that already has a conventional train line and a superhighway.

"It's incredibly costly, they're talking 13 billion euros," about $15 billion, said Marco Ponti, a transportation expert at Milan's Polytechnic Institute who backs the protesters.

Ponti likened the project to the English Channel rail tunnel, whose construction cost almost doubled from original estimates.

"The Channel tunnel went bankrupt not once, but twice," he said.

But Ponti, a former World Bank consultant, acknowledged that "there is a place for high-speed trains for medium distances and in very densely populated areas."

Still, the governments in Rome and Paris are throwing their full weight behind high-speed rail. West of Turin, engineers are blasting a tunnel through the craggy Alps, and this fall Italy took tenders on 30 very high-speed trains and says it wants to acquire 100 in all. Its master plan foresees building high-speed lines in the shape of a T, from Milan in the north to Naples in the south, and from Turin in the west to Venice in the east.

In Asia, too, the European train builders face challenges. For one, there is competition from Japan's fabled Shinkansen, the first high-speed train to go into service. A Shinkansen consortium led by Mitsui & Co. that includes many of Japan's top industrial companies was chosen by Taiwan for a 340-kilometer-an-hour train inaugurated last year from Taipei to the southern port of Kaoshiung. While Asian contracts are lucrative, most countries insist on technology transfers including the assembly of most of the trains in local factories.

Such requirements put pressure on the Europeans to continuously upgrade their technology or risk being overtaken by their own customers.

"The key is new technology," said Alstom's Lac? "The Chinese market is very interesting. They have the culture; they want to acquire the technology."