Chinese producer are offering cheaper products in the US and Europe

The surplus was $11.2bn (�6.4bn) from $2.45bn in February and $5.7bn a year earlier, the Ministry of Commerce said.

Premier Hu Jintao will visit the US this month and analysts expect renewed calls for China to allow its currency to strengthen against the dollar.

The US has accused China of keeping the yuan weak to boost exports and growth.

Growing partnership?

According to the most recent figures, exports in March rose 28.3% to $78.05bn from a year earlier, while imports advanced by 21.1% to $66.86bn.

"There are two stories at work," said Ben Simpfendorfer of the Royal Bank of Scotland. "The first is that we see surprising strength in exports. But imports are definitely weaker than I expected."

However, analysts said that the dip in imports was probably a result of a build up of commodities in previous months, rather than any significant decline in the strong demand that has been driven by China's rapid economic expansion and growth.

Analysts said that the size of the surplus was a shock as the first three months of a year are usually the weakest, and that there was a good chance it could now top the $100bn mark in 2006.

Mr Hu is due to arrive in the US on 20 April and trade is set to take centre stage in the talks.

One of the main topics in the US at present is the size of the trade deficit with China, with many industry leaders and politicians calling for measures to limit the amount of Asian goods imported into America.