BEIJING - China's manufacturing activity turned much more robust in November as a key non-official index jumped to 13-month high, indicating the Chinese economy is gaining momentum in the month.

The HSBC Flash China Manufacturing Purchasing Managers' Index (PMI) bounced back to expansionary territory for the first time in 13 months to stand at 50.4 in November, according to figures released by HSBC on Thursday.

The HSBC preliminary reading in November improved from October's final index of 49.5.

The manufacturing output index also shot up to a 13-month high of 51.3, compared with 48.2 in October. A reading above 50 suggests expansion, while a reading below 50 indicates contraction.

Sub-indexes on new orders, new export orders, stock of purchase and quantity of purchase in the manufacturing sector all increased in November, while the sub-reading on backlog of work and stockpiles shrank.

"The November flash reading of HSBC manufacturing PMI confirms again that the economic recovery continues to gain momentum toward the year end," said Hongbin Qu, chief economist for HSBC China.

Qu called for a continuation of policy easing from Chinese policymakers to strengthen the recovery as "it is still the early stage of recovery and the global economic growth remains fragile."

The sub-index on employment, however, continued to contract in November, suggesting Chinese manufacturers are still cautious in increasing hiring.

HSBC's preliminary reading on manufacturing was based on data the bank collected from 85 to 90 percent of the 420 manufacturing companies it surveyed from November 12 to 20, and it will publish its final November data on December 3.

The National Bureau of Statistics and the China Federation of Logistics and Purchasing are due to release official PMI data for November on December 1. The official PMI data is based on a survey of purchasing managers in more than 820 companies and 20 industries.