China's service sector activity rebounds to 17-month high: HSBC

China's service sector activity rallied significantly in August from the previous month, expanding at the fastest rate since March 2013, data company Markit said Wednesday.

The HSBC/Markit China Services Business Activity Index, which provides a snapshot of operating conditions in the sector, posted at 54.1, a strong rebound from the record low of 50.0 in July.

The HSBC/Markit Index samples over 400 private service sector companies in China.

Last month, China's service sector firms recorded a solid expansion of new business that was the strongest since January 2013, Markit said in the statement.

Backlogs of work at service sector firms fell for the second straight month in August, and at the quickest rate since November 2012.

Last month, China's service sector firms also raised their selling prices for the first time since March, albeit fractionally, it said.

August survey data signaled Chinese service providers were confident with the 12-month business outlook. Furthermore, the degree of positive sentiment strengthened to a five-month high.

"Apart from the rebound in the headline number, other indices suggest a mixed picture rather than a broad-based improvement (in China's economy)," said HSBC chief China economist Qu Hongbin.

China still faces downside risks to growth in the second half of the year from the property sector slowdown, Qu said, adding policymakers should use further easing measures to help support the recovery.

Also in the day, the official index for China's non-manufacturing sector, compiled by the National Bureau of Statistics and the China Federation of Logistics and Purchasing, was released.

The official index of the non-manufacturing sector rebounded to 54.4 percent last month. The reading stopped the losing streak since June and continued to stay above the 50-threshold that demarcates expansion and contraction, official data suggested.