BEIJING - CHINA'S wealth gap between urban and rural residents is widening, state media said on Thursday, a potentially explosive issue that has long worried the nation's communist rulers.

City residents earned 3.28 times as much as those living in the countryside last year, compared to 3.23 times in 2003, the Xinhua news agency quoted agricultural minister Sun Zhengcai as saying.

In his report to the nation's legislature, he said the yearly net income of China's 900 million rural residents rose seven percent to 4,000 yuan (S$792) in 2007.

In the financial hub of Shanghai the annual gross salary per capita for a worker last year was nearly 30,000 yuan or more than 2,400 yuan per month, according to Shanghai labour bureau statistics.

The growing inequality has accompanied China's huge economic boom, as Beijing has repeatedly vowed to improve the lot of its destitute farmers by spending more on health care, education and economic development.

China's leadership remains increasingly worried about the income gap brought about by 30 years of market reforms that have made a few Chinese cities very rich, but raised tensions in the nation's hinterland.

Complaints in the countryside over high taxes and fees, illegal land grabs and pollution have repeatedly sparked protests that at times turn violent with tragic consequences.

Despite an increase in spending on agricultural, rural workers and farmers to 431.8 billion yuan this year, an increase of 80.1 billion yuan over the previous year, the countryside remains woefully behind, Mr Sun said. -- AFP