Shanghai, once held in awe as the Paris of the East and an adventurer's paradise, is now pitied by China's rulers and cursed by many who live there.

Foreign businessmen working in the city say the problem is simple: The city is antique.Shanghai's outmoded infrastructure - from streets to sewers to telephones - must be overhauled, and the only way may be to demolish its famed but aging buildings.

Those buildings are a link to an era when Shanghai boasted Asia's smartest shops and liveliest nightspots, and gangster Du Yuesheng ran its most infamous underworld.

"Most of old Shanghai will be destroyed sooner or later," said Gui Mingqi, a Shanghai official. "Chinese here are really beginning to hate those old buildings."

Foreign businessmen said delays and frustrations caused by the city's outmoded facilities were so acute that they were driving would-be investors away.

"I think Shanghai's overloaded infrastructure discourages some foreign businessmen from investing here," said the manager of Mitsui and Co.'s foodstuffs division.

He said some of the goods the big Japanese company buys from areas surrounding Shanghai took so long in transit they missed ships scheduled to carry them overseas.

Even when they arrived in time, there was invariably a long wait because of port delays.

"The longest wait we had was more than 45 days. That is a very long time for perishable goods to be in a warehouse," he said.

"At the quickest, the goods must wait two weeks. In Japan it would take a week," he said.

Most of present-day Shanghai was planned before the 1920s by French, British, American and later Japanese colonial overlords trying to recreate some of the genteel pleasures of home.

But since then China's population has more than doubled, and Shanghai's has swollen to 12 million.

Industrial waste gushes into the mighty Yangtze River, and recycled tap water tastes foul.

Cargo boats bob aimlessly at anchor, waiting to unload. Narrow roads built for rickshaws are clogged with traffic.

Public transport is slow, empty taxis are rare.

"All businessmen who have been living in the Peace Hotel for a long time know they must give the taxi rank controllers cigarettes and other presents," said a foreign resident. "Otherwise they do not get a taxi."

On one day last month, 30 of the plush Sheraton Hotel's 32 cabs were booked before the day had even begun.

Businessmen said they had to dial telephone numbers an average of 15 times before they were connected. It is impossible to dial directly outside the city on most public telephones.

A Japanese student, injured in a rail crash that killed 27 of her schoolmates on the outskirts of Shanghai several weeks ago, said she was stalled in traffic for hours en route to the hospital.

"Shanghai people must realize that they are no longer China's number one," said Zhu Rongji, head of Shanghai's delegation to China's parliament.

"Its industrial growth rate is now the lowest of all major Chinese cities," he said.

"In order to open to the outside world, Shanghai must do a lot to improve its infrastructure," said Zhu. "Transport is the biggest headache."

He said the city planned to attract $10 to $20 billion in foreign investment over the next three to five years.

Zhu said he was confident the city could turn the corner on its troubles.

Shanghai plans to build a subway rail system, install a new telephone exchange, a sewage treatment plant, an airport terminal and a bridge spanning the Huangpu River in addition to one already under construction.

These projects would be completed by the early 1990s, according to Zhu.

This year the city will begin turning over a fixed tax sum to the central government instead of a percentage of its own receipts. That is expected to save the city a lot of badly needed money over the next few years.

Officials said some of that would be used to widen inner city streets and demolish some of the old colonial-style buildings that line them.