Air freight capacity out of mainland China and Hong Kong was almost fully booked in December, according to shippers, making it likely that China would post strong exports when it released a flood of monthly and annual economic data next week. But in interviews this week, senior corporate executives voiced a range of opinions about whether this strength would continue into the new year, or whether the surge in December represented a flurry of restocking by retailers who went into the Christmas season with meager inventories.

Victor Fung, the nonexecutive chairman of Li & Fung, a Hong Kong-based trading and supply chain management company that is one of the world’s largest, said that overseas demand had not been strong enough to sustain the strength in China's shipments seen last month. But he added that his own staff was somewhat more optimistic than he is, as are some investment bank economists.

Thursday's slight increase in interest rates could prove even more significant if it marks the start of an effort by Chinese regulators to limit bank lending. Chinese banks have not only lent heavily at home, but stepped up lending in other countries as well, taking market share from Western banks hobbled by the global financial crisis.

Top officials at the People's Bank of China concluded an annual two-day policy review on Wednesday with a lengthy statement that had particularly strong cautions against bank lending to sectors of the economy with overcapacity or excessive energy use. Chinese bank regulators also warned banks in late November to show more caution in lending and raise more capital to underpin the surge in lending they have already done; the publicly traded Bank of China is widely expected to take the lead in raising money this year.

Thursday's interest rate increase is not the first since the bottom of the economic downturn. After cutting interest rates on the same 3-month central bank bills by 2.4 percentage points in the last quarter of 2008 as the world's financial system trembled, the People's Bank nudged up interest rates by 0.363 from late June to early August last year in a series of increasingly large weekly increases.

But the central bank has been on hold ever since, watching for more evidence of the economy's health. Thursday's increase appeared to confirm that the central bank was starting to become concerned again about rising prices, economists said.