BEIJING - ABOUT 600,000 migrant workers left south China's industrial heartland last year as the economic crisis caused exports to shrink and forced factories to close, a senior official said on Thursday.

The number of migrants departing Guangdong province, one of the world's top makers of toys and electronic appliances, accelerated in 2008 as the situation worsened, said provincial deputy governor Huang Longyun.

'This year the situation is more serious than at any other time since the start of the decade, indeed since the Asian financial crisis,' he told a briefing in Beijing.

By the middle of last year, when the financial crisis was still in its embryonic stage, only 143,100 had left Guangdong, but the number reached half a million at the end of October and has now hit 600,000.

Guangdong's export sector may have been the single most important factor in China's economic boom, and it has been helped by migrant workers who have gone to the province from China's destitute interior in search of better lives.

Mr Huang did not give an overall figure for the number of migrant workers in the province, but earlier data said they numbered between 25 and 30 million.

Data unveiled at the briefing showed why the migrants were leaving, stating that Guangdong's economy grew by 10.1 per cent last year, down from 14.7 per cent in 2007.

Exports, the lifeblood of the province, expanded by just 5.6 per cent in 2008, down from 22.3 per cent the year before, the statistics indicated.

The health of Guangdong is essential for China's overall wellbeing, as the Pearl River Delta, the province's most active economic area, provides much of the nation's growth impetus.

Together with the Yangtze River Delta further north it takes up just 2.6 per cent of China's land area, but accounts for one third of its gross domestic product and 40 per cent of its fiscal revenues, according to government data. -- AFP