BEIJING, Oct. 21 -- China's industrial production growth picked up to 8 percent year on year in September after a sharp slowdown to 6.9 percent in August, official data showed on Tuesday.

The growth rate was also 0.5 percentage points higher than the market consensus projection. The 6.9 percent in August was the weakest growth since December 2008.

"The growth of industrial production remained stable," the National Bureau of Statistics (NBS) said in a statement.

For the first nine months, industrial production growth decelerated to 8.5 percent year on year, down 0.3 percentage points from that of the first half of 2014.

On a month-to-month basis, the industrial output in September expanded by 0.91 percent from the previous month, much higher than the fractional 0.22-percent growth recorded in August, the NBS said.

September's rebound in China's industrial activity is encouraging, Nomura Securities said in a research note.

"Of all the monthly data, industrial production has the strongest correlation with GDP growth, so this bodes well for an economic recovery this quarter," it said.

China uses industrial production, officially called industrial value added, to measure the business activities of designated large enterprises, each with annual turnover of at least 20 million yuan (3.25 million U.S. dollars).

Industrial production accounted for 44.2 percent of China's total GDP in the first nine months, making it one of the best leading indicators for China's GDP growth.

China's gross domestic product expanded at a slower pace of 7.3 percent in the third quarter of this year, but still remained within the "reasonable range" set by policymakers.

The industrial output rebound in September was led by stronger output of chemicals, steel, and a sharp acceleration in the telecommunication and computer sector -- likely reflecting September's iPhone launch and strong demand for devices from Xiaomi, another popular smartphone brand, said Barclays chief China economist Chang Jian in a note.

Chemical materials output rose by 10.4 percent year on year last month, while steel output picked up to 5.5 percent year on year. A particularly strong rise was seen in mobile and PCs, which saw growth surge to 16.6 percent, up from August's 9.6 percent.

Power generation also recovered, rising 1.6 percent, compared with a 1.7-percent contraction in August. Offsetting the broadly stronger industrial production output was slightly weaker textiles output growth of 5.3 percent year on year, down from 5.7 percent in August.

NBS data showed that the value-added industrial output of state-owned and state-controlled enterprises saw 5.2-percent growth year on year in the first three quarters, while that of joint stock companies expanded by 9.9 percent. Industrial output of enterprises funded by overseas investors expanded by 6.7 percent in the period.

Value-added industrial output in the manufacturing sector rose 9.6 percent year on year in the first nine months. That of the mining sector rose by 4.8 percent.

Out of 464 types of industrial products, 346 types posted year-on-year growth in output. In the first three quarters, the sale-to-output ratio of designated industrial enterprises stood at 97.7 percent, or 0.2 percentage points higher than the first half of this year, data showed.

From January to August, total profits of such enterprises grew 10 percent year on year to 3.83 trillion yuan, NBS data showed.

Nomura also said the next key data point to watch for signs of stabilizing or improving industrial output growth is the HSBC/Markit flash China manufacturing purchasing manager's index on Thursday, which Nomura expects to hold steady at 50.2.