Chinese imports posted an unexpectedly sharp drop in December, flashing a warning sign that the world's second-largest economy is expanding at a slower rate. Meanwhile, full-year figures pointed to a narrowing trend in the Chinese trade gap, which suggest the country is relying more on domestic demand.

December growth in imports fell to 11.8 percent, about half of November's 22.1 percent gain, according to data released Tuesday by the General Administration of Customs. Exports rose 13.4 percent, down slightly from the 13.8 percent rise recorded in the previous month.

That left China with a trade surplus of $16.5 billion on the month and $155.2 billion on the year, the third consecutive annual decline after reaching a record $298 billion in 2008.

China has been a relatively bright spot in the sluggish global economy. However, Tuesday's data sends a worrying signal that China is slowing down.

China's rapid economic growth slowed to 9.1 percent in the three months ending in September from 9.6 percent the previous quarter and 2010's double-digit expansion. Beijing has responded by reducing banks' cash reserve requirements by 50 basis points in November to 21 percent, the first such cut in three years in an effort to boost corporate credit lines.

Beijing also faces pressure from Washington over currency controls, which is said to have given the Chinese exporters an unfair advantage and have hurt foreign competitors.