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By Samuel Shen and Kazunori Takada
SHANGHAI, May 8 (Reuters) - China stocks rebounded on Friday, stemming a three-day sell-off that led a key share index to its worst weekly decline in nearly five years amid fears of regulatory crackdown on speculators.
The Shanghai Composite Index rose 2.3 percent, to 4,205.92 points. But for the week, the Shanghai index fell 5.3 percent, posting its worst performance since July 2010.
The CSI300 index climbed 2.0 percent, to 4,558.40, but posting a weekly decline of 4 percent, the biggest in one and a half years.
The poor performance was triggered by signs of tighter regulatory scrutiny over margin lending, which has helped fuel a near doubling in China's stock market over the past year despite a flagging economy.
Data on Friday showed that China's exports unexpectedly fell 6.4 percent in April from a year earlier, while imports tumbled by a deeper-than-forecast 16.2 percent.
The poor trade figures reinforced expectations of that Beijing will deliver fresh stimulus, and were interpreted as being good news to the stock market, according to Gerry Alfonso, director of Shenwan Hongyuan Securities Co.
He said Friday's improvement in sentiment was also "likely caused by investors seeing opportunities after three days of corrections."
Shenzhen's start-up board ChiNext surged 6 percent on Friday to record highs, the indexes' biggest one-day rise in four and a half years.
Technology related stocks also jumped, after the government vowed to vigorously promote e-commerce and expedite funding by Internet companies.
But banking shares rose slightly, with some analysts attributing the underperformance to rising bad debts in the first quarter.
Real estate shares also lagged the rise in the broader market. (Reporting by the Shanghai Newsroom; Editing by Simon Cameron-Moore)