A private survey says China's manufacturing activity edged up to a four-month high in February although export orders decreased for the first time since April.

HSBC's preliminary purchasing managers' index released Wednesday rose to 50.1 this month from 49.7 in January.

The index is based on a 100-point scale on which numbers below 50 indicate contraction.

The report said there was a "marginal improvement" in China's manufacturing sector heading into the Lunar New Year period, though domestic demand would likely "remain sluggish" while foreign demand "looks uncertain."

China's economy grew last year at its slowest pace in nearly a quarter-century and economists forecast further slowing.

The data may be distorted by the Lunar New Year Holiday, which falls at different times in January or February each year.