SHANGHAI: China shares closed lower on Thursday, turning around from small gains at midday as a rebound in consumer firms faltered, after a private survey showed that services activity growth slowed in May.

At the close, the Shanghai Composite index was down 0.36% at 3,584.21 and the blue-chip CSI300 index 0.66% lower, with both indexes reversing intraday gains.

The consumer staples sector gave up most of its gains for the day to finish just 0.09% higher, down from a 1.46% rise at midday. The healthcare sub-index fell 1.25%.

Healthcare and consumer firms have swung between losses and gains this week as investors weigh the impact of Beijing's announcement that married couples can have up to three children.

The wobbly performance of consumer shares followed a private sector survey that showed a slower expansion in China's services sector activity in May.

Banks were among the biggest drags on the CSI300 index, with a sub-index tracking the sector down 0.71% on the day. The CSI300 financial sector sub-index fell 0.56%.

The lower close came a day after China's margin trading balance amount, an indicator of investor sentiment, hit its highest level since July 2015, as investors borrowed more to purchase shares amid a stock rally.

The smaller Shenzhen index ended down 0.34% and the start-up board ChiNext Composite index was 1.272% weaker.