China's manufacturing purchasing managers' index (PMI) for April fell to a 12-month low of 49.2, according to a reading by HSBC released on Thursday.
A reading above 50 indicates expansion, while a reading below 50 represents contraction.
The HSBC/Markit flash China manufacturing output index, a sub-index of PMI, posted 50.4 this month, a three-month low, data company Markit said in a statement.
The HSBC flash manufacturing PMI for April came after an official reading of 50.1 in March.
The HSBC Flash China Manufacturing PMI is published on a monthly basis ahead of final PMI data, which will be released on May 4, according to the statement.
The estimate is typically based on approximately 85-90 percent of total PMI survey responses each month.
The flash reading of the PMI signaled that "operating conditions in China's manufacturing sector deteriorated slightly for the second month running in April. Production increased only marginally, while total new business declined for the second successive month," said Annabel Fiddes, an economist at Markit.
On a brighter note, demand from overseas improved in April, with new export work rising for the first time in three months, Fiddes added.
The PMI is a composite index based on five of the individual indexes with different weights: new orders, output, employment, suppliers' delivery times and stock of items purchased.
