China's manufacturing activity expanded for a second straight month in September, HSBC reported on Monday, suggesting a rebound in the world's second-biggest economy is building momentum.

The bank's closely watched purchasing managers' index (PMI) for the month rose to 50.2 from 50.1 in August and well up from an 11-month low of 47.7 seen in July.

A reading higher than 50 signals growth while anything below that indicates contraction.

"Though only slight, this was a positive development," the British banking giant said in a statement.

The news is the latest sign that the Asian economic giant is picking up speed after suffering a slowdown at the start of the year.

The economy registered growth of 7.7 percent in 2012 -- the worst performance in 13 years -- 7.7 percent in the first three months of this year and 7.5 percent in April-June.

But recent data, including strong exports and industrial output, have pointed to renewed strength.

China has refrained from introducing major stimulus measures, but in late July it announced a number of steps to bolster growth, including reducing taxes on small companies and encouraging railway development.

Authorities would likely maintain small-scale efforts to support growth, HSBC chief economist Qu Hongbin said in a statement.

"Growth is bottoming out on Beijing's mini-stimulus," Qu said. "We expect continuous policy efforts to sustain the recovery."