China launched its first aircraft carrier for a maiden run on Wednesday, a step likely to boost patriotic pride at home and jitters abroad about Beijing's naval ambitions.

The long-awaited debut of the vessel, a refitted former Soviet craft, marked a step forward in China's long-term plan to build a carrier force that can project power into the Asian region, where seas are spanned by busy shipping lanes and thorny territorial disputes.

"Its symbolic significance outweighs its practical significance," said Ni Lexiong, an expert on Chinese maritime policy at the Shanghai University of Political Science and Law.

"We're already a maritime power, and so we need an appropriate force, whether that's aircraft carriers or battleships, just like the United States or the British empire did," he said in a telephone interview.

The carrier "left its shipyard in Dalian Port in northeast Liaoning province on Wednesday morning to start its first sea trial," said the official Xinhua news agency, describing the trip as a tentative test run for the unfinished ship.

The aircraft carrier, which is about 300 meters (984 feet) long, plowed through fog and sounded its horn three times as it left the dock, Xinhua said on its military news microblog.

Xinhua said that "building a strong navy that is commensurate with China's rising status is a necessary step and an inevitable choice for the country to safeguard its increasingly globalised national interests."

Chinese citizens said the carrier launch showed their country deserved more respect from the rest of the world, despite problems it faces at home.

A high-speed train crash last month left many Chinese people bemoaning what they called officials' reckless hunger for passing technological milestones.

"An aircraft carrier is the mark of major powers," Pan Chunli, a 29-year-old IT technician in Beijing told Reuters.

"China has grown dramatically. The whole world should take a fresh look at China, viewing it as a rising power that it has the ability to defend its rights and territory."

Retired Chinese navy Rear Admiral Yin Zhuo told state-run television that his country intended to build an air carrier group, but the task would be long and difficult.

"As for forming a carrier group, I think that will take at least ten years," he told a Chinese television broadcast on the carrier launch.

PRESTIGE AND POWER

Last month, China confirmed that it was refitting the old, unfinished Soviet carrier hull bought from Ukraine's government, and sources told Reuters it was also building two of its own carriers.

"China has had a longstanding fascination with the national prestige attached to aircraft carriers, and this first sea trial may be seen as a crucial step toward the goal of achieving great naval power status," said Chengxin Pan, an expert on China at Deakin University in Australia.

If Beijing is serious about having a viable carrier strike group, however, it will need three carriers, Ashley Townshend at the Lowy Institute for International Policy in Sydney told Reuters in an interview before the debut of the vessel.

China would also have to develop support ships and aircraft for any carrier group, Townshend said.

In China's neighborhood, India and Thailand already have aircraft carriers, and Australia has ordered two multi-purpose carriers. The United States operates 11 carriers.

Before the launch, a Pentagon spokesman played down the likelihood of any immediate leaps from China's carrier program. U.S. experts on the Chinese navy agreed.

"A newly-wed couple wants a 'starter home', a new great power wants a 'starter carrier'," Andrew Erickson of the U.S. Naval War College and Gabriel Collins, a security analyst, wrote in a note about the carrier launch (www.andrewerickson.com).

"China's 'starter carrier' is of very limited military utility, and will primarily serve to confer prestige on a rising great power, to help the military master basic procedures, and to project a bit of power," they wrote.

LONG-STANDING DISPUTES

But the carrier is just one part of China's naval modernization drive, which has forged ahead while other powers tighten their military budgets to cope with debt woes.

"For many neighbors, it may symbolize something different and more unsettling," said Pan, the Deakin University lecturer, referring to China's carrier.

"It is inevitable that neighboring countries will react with some alarm, especially given recent disputes in the South China Sea as well as the maritime incident between China and Japan last year," he said.

China has been building new submarines, ships and anti-ship ballistic missiles as part of its naval modernization.

The country's growing reach at sea is triggering regional jitters that have fed into long-standing territorial disputes, and could speed up military expansion across Asia.

In the past year, China has had run-ins at sea with Japan, Vietnam and the Philippines. The incidents -- boat crashes and charges of territorial incursions -- have been minor, but the diplomatic fallout often heated.

"They want to assert their dominance in East Asia as well as the Chinese sea and they have very ambitious plans of asserting their claims over some islands," retired Indian Major General Ashok Mehta, a defense analyst in Delhi, said of China.

"India has lot of catching up to do and the history of India's catching up is not very impressive," he said, noting New Delhi's plan to have three aircraft carriers by 2015.

Last week, Japan warned that China's naval forces were likely to increase activities around its waters.

But China did not want to rile its neighbors with the carrier debut, said Ni, the Shanghai professor.

"A single, solitary aircraft carrier floating on the sea, without the accompanying forces, doesn't constitute a battle force," said Ni. "It would be a sitting duck if you tried to send it out."