China's runaway stocks rally stuttered and commodities struggled to find a footing on Wednesday as investors tempered their expectations for a robust Chinese economic recovery, keeping pressure on shares globally.

Chinese stocks came under pressure on Tuesday after a disappointing update from the government tempered some of the exuberance that has propelled Chinese equities out of a bear market in recent weeks.

A highly anticipated press briefing by China's top economic planner fell short of expectations.

By Tom Westbrook SINGAPORE (Reuters) -Chinese shares slumped and commodities were struggling to find a footing on Wednesday as investors tempered expectations for a robust Chinese economic recovery, while a downbeat outlook from New Zealand's central bank sent the kiwi to a seven-week low.

Shares in mainland China plunged as traders expressed their disappointment with the lack of new stimulus. The U.S. government's possible attempt to break up Google weighed on tech.

Chinese shares fell on Wednesday and commodities nursed sharp losses as investors tempered enthusiasm for a Chinese economic recovery, while broader markets steadied on expectations that the U.S. economy can avoid recession and support global demand.

Shares in mainland China soared at the opening, as markets reopened after the Golden Week holidays. But they slid back as the stimulus plans provided by China's economic planning agency seemed to underwhelm investors.

Chinese stocks rallied in the first day back from their long holiday, but disappointment over no further stimulus saw gains pared.

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.