China's consumer price index rose 4.4%

The move came Wednesday just after China reported its second-largest monthly trade surplus this year, and highlighted the nation's unusual economic position ahead of this week's summit of the Group of 20 major economies in Seoul. China and some other emerging markets are increasingly concerned that their strong economic rebound from last year's global slowdown will result in inflation and asset bubbles, while the U.S. and other developed economies are expanding weakly if at all.

China's reserve requirement ratio for banks will rise by half a percentage point starting next week, the People's Bank of China said in a statement on its website Wednesday. That would put the standard ratio for large banks up to 17.5%, though the actual requirement imposed on individual banks can be higher or lower at the central bank's discretion.

'Beijing's policy focus has shifted decisively from concerns about domestic growth and external demand to concerns about inflation pressures and liquidity management,' said Brian Jackson, an economist at Royal Bank of Canada. As is its usual practice, the central bank offered no commentary on or explanation of its decision.

Requiring banks to keep more money at the central bank will drain funds from the financial system, helping relieve some of the inflationary pressures.

Those concerns appear to have been heightened by the shift in U.S. monetary policy. Central bank Gov. Zhou Xiaochuan said last week that while the Federal Reserve's plan to start buying bonds again may make sense for the U.S., it could still have undesirable effects on the world economy. He warned that the policy, sometimes known as quantitative easing, could cause a surge of capital inflows into China that would complicate its economic management.

Also Wednesday, Zhou Wangjun, a vice director of the price department of the National Development and Reform Commission─China's top economic planning agency─blamed the recent surge in global commodity prices on the Federal Reserve's quantitative easing policy.

Earlier this year, the central bank raised the reserve-requirement ratio three times, but stopped after May as worries about the possibility of a sharp slowdown in the world economy grew. In the event, China's economic growth stabilized, and some economists think it may even have re-accelerated in the last few months.

The central bank renewed its effort to tighten monetary policy in October, when it raised benchmark interest rates for the first time in three years. Last week it said in a report that it will 'continue to guide monetary conditions gradually back to a normal level' from the recent crisis-response mode, a statement that many economists have read as signaling more interest-rate increases to come. Beijing has also adopted a series of measures to cool the real-estate market and curb speculation.

Those policies have led to some moderation in China's growth, and China's Customs agency reported separately Wednesday that the nation's merchandise trade surplus rose to $27.15 billion in October from $16.9 billion in September, as imports, particularly of commodities, cooled down. China was running much smaller surpluses earlier this year, when imports were growing by more than 50%, but its trade surplus started to grow again in May as those gains tailed off.

The U.S. and other countries have long been seeking a stronger Chinese currency in order to narrow the trade gap, with limited success. But the trade data did come after China's central bank on Wednesday set the yuan's central parity rate─a reference for daily trading─at a fresh high against the dollar of 6.6450. The yuan has now risen 2.9% against the U.S. dollar since China's June pledge to allow greater exchange-rate flexibility.