BEIJING, Aug 24 (Reuters) - Days of downpours brought by Typhoon Sepat have displaced more than 757,000 people in a southern Chinese province, where seven were killed as rivers overflowed to historic high levels, state media said on Friday.

An average 119 mm (4.7 inches) of rain fell on the rice-growing Hunan province between Sunday, when Sepat slammed into China's southeast coast, and Friday, Xinhua news agency said.

Hundreds of thousands of residents were mobilised to scour for breaches in the banks of the swollen Xiang River and its tributaries, which have in the past submerged three county-level cities, Xinhua said.

Seven people died and another five went missing in the floods in the inland province, it said.

Although Sepat weakened into a tropical depression soon after landing, it has already killed 39 residents in several other provinces in south and east China, most of whom died in floods and landslides triggered by torrential rains.

While the rain helped ease a months-long drought, large areas of crops were destroyed, 15,000 houses damaged and scores of roads cut off in Hunan, causing direct economic losses of 5.6 billion yuan ($740 million), Xinhua said.

Troops used speed boats to rescue tens of thousands of residents stranded in flood waters, the report added.

Flooding is a perennial woe for China and claims hundreds of lives every summer. The death toll has been about 1,000 so far this year.

Tropical Storm Bilis killed more than 400 people in Hunan in July 2006 with days of downpours.

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