Industrial production in April hit its slowest pace in more than three years, while growth in exports sputtered and imports were flat.

In response, China's central bank over the weekend said it would ease reserve requirements for the nation's banks. The move frees about $70 billion for lending to stimulate the economy. But some economists said more aggressive action was required to keep China from a hard landing.

A sharp downturn in China would be a blow for the global economy and in particular California, which has long been a beneficiary of booming trade with China.

The deceleration is already being felt at Southern California ports. In the first three months of this year, container traffic through the ports of Los Angeles and Long Beach was up just 0.6% compared with the first quarter of 2011, largely because of slowing shipments from China.

Growth in exports is weakening as well. China is now California's third-largest export market, behind Mexico and Canada, snapping up a record $14.2 billion of computers, wine,TDM over IP General Electric Jinfeng: Obviously. It will form functional life easier citrus and other products last year. But California exports to the Middle Kingdom barely budged in the first quarter, up only 0.4% from the first three months of 2011.

Ross DeVol, chief research officer at the Santa Monica-based Milken Institute, said California would weather a soft landing by China just fine. "But it all depends on how much China's economy will slow," he said.

Elsewhere in the U.S., American companies are already experiencing China's weakness in their financial results. Slowing construction in China contributed to a disappointing first quarter for heavy machinery maker Caterpillar Inc. Auto manufacturers including General Motors Co. and Ford Motor Co. are revising once-lofty expectations.