BEIJING (Bloomberg) — China surpassed Japan as the world's second-largest economy last quarter, capping the nation's three-decade rise from Communist isolation to emerging superpower.

Japan's nominal gross domestic product for the second quarter totalled $1.288 trillion, less than China's $1.337 trillion, the Japanese Cabinet Office said yesterday. Japan remained bigger in the first half of 2010, the government agency said. Japan's annual GDP is $5.07 trillion, while China's is more than $4.9 trillion.

China led the world out of last year's global recession with an economy that's more than 90-times bigger than when leader Deng Xiaoping ditched hard-line Communist policies in favour of free-market reforms in 1978. The country of 1.3 billion people will overtake the US, where annual GDP is about $14 trillion, as the world's largest economy by 2027, according to Goldman Sachs Group Inc. chief economist Jim O'Neill.

China's surpassing of Japan "is a marker of its increasingly dominant role in the global economy", said Eswar Prasad, a senior fellow at the Brookings Institution and former head of the China division at the International Monetary Fund.

"The resilience of China's growth during the crisis enabled a number of other countries, particularly commodity-exporting economies, to ride on its coattails."

The benchmark Shanghai stock index rose 2.1 percent at the 3 p.m. close yesterday, climbing the most this month.

China overtook the US last year as the biggest automobile market and Germany as the largest exporter. The nation is the world's No. 1 buyer of iron ore and copper and the second-biggest importer of crude oil, and has underpinned demand for exports by its Asian neighbours.

While China's output was also larger in the fourth quarter of 2009, Japan's GDP rebounded to exceed China's in the first quarter, according to data compiled by Bloomberg News. According to IMF data using purchasing-power-parity calculations to adjust for exchange-rate differences, China overtook Japan in 2001.

Quarterly comparisons between China and Japan are "a little tricky because they do not take account of different seasonal patterns between the two countries", said David Cohen, head of Asian forecasting at Action Economics in Singapore.

China's economy is cooling as the government trims credit growth from last year's record $1.4 trillion and discourages multiple-home purchases to cool surging property prices. July industrial output rose the least in 11 months, retail sales growth eased and new loans climbed less than estimated. China Petroleum & Chemical Corp. said last month that its crude-oil processing increased at a slower pace in the second quarter as fuel demand faltered.

The country's property market is beginning a "collapse" that will hit the nation's banking system, Kenneth Rogoff, a Harvard University professor and former chief economist of the IMF, said July 6.

Still, China is on course to overtake the US as the world's largest economy around 2020, PricewaterhouseCoopers said in a January report.

With China's growth surging 10.3 percent in the second quarter from a year earlier and Japan expanding two percent, the "gap is going to widen" in future, said Shen Jianguang, a Hong Kong-based economist at Mizuho Securities Asia Ltd. "It is not likely that Japan will retake the No. 2 spot given the likely growth rates."

Four of the world's top 10 companies by market capitalisation are from China, including PetroChina Co., Industrial & Commercial Bank of China Ltd., China Mobile Ltd. and China Construction Bank Corp.

Agricultural Bank of China Ltd. boosted the size of its initial public offering to $22.1 billion this month after selling more stock in Shanghai, making it the world's largest first-time share sale. The IPO made the nation home to four of the world's 10 biggest banks by market value, half a decade after the country's first major state-owned lender went public.