Chinese shares have plunged again, with Shanghai's benchmark down 6.6% and Hong Kong's losing 1.5%. Investors have been dumping shares to lock in profits after recent rallies driven by hopes for major economic stimulus.

European stocks fluctuated at the open on Wednesday as investors assessed the impact of a faltering rally in Chinese shares on sectors most exposed to the world’s second biggest economy.

China's stock markets roared back from a week-long break to reach their highest levels in more than two years at the open, before paring gains after officials failed to inspire confidence in stimulus plans intended to revive the economy.