Updated

A survey of Chinese factories says manufacturing activity contracted in December in another sign the slowdown in the world's No. 2 economy is quickening.

HSBC's preliminary purchasing managers' index released Tuesday fell to a seven month low of 49.5 from 50 in November.

The index uses a 100-point scale on which numbers above 50 indicate expansion.

It's the latest in a string of weak data on China's economy, which expanded at a five-year low of 7.3 percent last quarter. That rate was below the official full year target of 7.5 percent.

Other recent official data for November showed that growth in industrial production slowed to 7.2 percent while imports contracted unexpectedly.