A skyscraper building boom in China and India may be a sign of an impending economic collapse, according to financial experts.

Barclays Capital has mapped an "unhealthy correlation" between construction of the world's tallest buildings and looming financial crises over the last 140 years, including the Great Depression and the Asian financial crisis.

Today, China is home to over half the 124 skyscrapers now under construction worldwide.

India, which has just two skyscrapers, is building 14, including the world's second tallest tower, in the financial capital Mumbai.

Barclays said the clusters of building activity usually coincide with periods of easy credit, excessive optimism and rising land prices, which often occur before market corrections.

"Building booms are a sign of excess credit," Andrew Lawrence of Barclays Capital in Hong Kong, said.

Historically, skyscraper construction has been characterised by bursts of sporadic, but intense activity that coincide with easy credit, rising land prices and excessive optimism, but often by the time skyscrapers are finished, the economy has slipped into recession, Mr Lawrence said.

The Great Depression hit as the finishing touches were being put on three record-breaking buildings in New York: 40 Wall Street, the Chrysler Buildingand the Empire State Building, which were all completed between 1929 and 1931.

The economic and oil crises of the 1970s coincided with the completion of the twin towers at New York's World Trade Centre, in 1972 and 1973, and Chicago's Sears Tower in 1974.

The Asian financial crisis hit as Kuala Lumpur's Petronas Towers were finished in 1997.

Dubai's $4.1bn Burj Khalifa, completed in 2010, is now the world's tallest building. As it was being built, Dubai nearly went bust and the world slid into the Great Recession.

"Thankfully for the world economy, there is not currently a skyscraper under construction that is planned to overtake the height of the Burj Khalifa," the report said.

However, signs of trouble are escalating in China and India.

Today, China has the dubious distinction of being the world's "biggest bubble builder," as it erects ever more and ever higher towers, Barclays said. Home to 53% of the 124 skyscrapers now under construction globally, China is primed to increase its stock of skyscrapers by 87%.

About 80% of new buildings are going up in tier two and three cities, away from developed coastal areas of the Pearl River Delta and Yangtze River Delta, which Barclays called "evidence of the expanding building bubble."

Mr Lawrence said China's property market is already wobbling.

The number of residential property sales has decreased 40 to 50% in Beijing and Shanghai and developers have slashed prices 5 to 20%, he said.

India takes top honours for hubris: The second tallest building in the world, the Tower of India, is now under construction in Mumbai.