BEIJING - The purchasing managers' index (PMI) for China's manufacturing sector remained stable at 50.1 in April, slightly down from 50.5 in March, the National Bureau of Statistics (NBS) said Tuesday.

A reading above 50 indicates expansion, while a reading below reflects contraction.

Although down from a month ago, the PMI was still the second highest since November and stayed above the boom-bust line for two consecutive months, NBS senior statistician Zhao Qinghe said.

High-tech manufacturing continued to lead the trend and imports and exports showed warming signs, he said.

The PMI from high-tech manufacturers was on a gaining streak for a fourth straight month in April, standing at 52.9, far above the overall level. Tech firms surveyed saw the best improvement in new orders in 10 months.

"Businesses reported better profit margins, in particular the ferrous metal processing industry," Zhao said. "The performances of small enterprises also improved as recent targeted tax cuts and other policy support began to take effect."

The sub-indices for production and new orders came in at 52.1 and 51.4 respectively, both showing robust momentum.

Tuesday's data also showed the service activity eased pace but maintained steady expansion in April as the non-manufacturing PMI came in at 54.3, down from 54.8 in March.