* Daily crude steel output at 2.7 mln T in Sept
* China Q3 GDP growth slowest since 2009
(Updates prices)
By Manolo Serapio Jr
MANILA, Oct 19 (Reuters) - Chinese steel prices fell on Friday after data showed daily output in the world's top steel producer climbed to a record in September and China's economy slowed to the weakest pace since 2009.
The increased steel production came as mills chased strong prices and ahead of China-led output curbs during winter as the country aims for clearer skies.
The most actively traded January rebar on the Shanghai Futures Exchange SRBcv1 closed down 2.4 percent at 4,055 yuan ($585) a tonne. Hot rolled coil SHHCcv1 dropped 1.4 percent to 3,860 yuan.
China's crude steel production reached 80.85 million tonnes last month, up from August's 80.33 million tonnes and from 71.83 million tonnes in September last year, government data showed.
That put average daily output in September at 2.7 million tonnes, the highest on record, according to Reuters' calculation. profits are still very high and that's the reason why everyone is increasing production, to maximise their profits," said Helen Lau, analyst at Argonaut Securities in Hong Kong.
The average profit margin at steel mills is currently running above 1,000 yuan a tonne, according to Huatai Futures.
The impact of government-led production curbs over winter would be the key driver for output in the fourth quarter, although Lau said they are likely to be more relaxed compared with last year's.
China allowed local governments to set their own winter production restrictions this year, ditching last year's blanket limits.
In Tangshan, China's top steelmaking city, mills continued to ramp up output this month in the absence of detailed orders from the city government. weighing on prices, China's economy grew less than expected at 6.5 percent in the third quarter from a year earlier, marking its weakest expansion since the global financial crisis amid a trade war with the United States. of steelmaking ingredients also declined. The most-traded iron ore on the Dalian Commodity Exchange DCIOcv1 fell 1.6 percent to 515 yuan a tonne.
Coking coal DJMcv1 slid 2.6 percent to 1,356 yuan a tonne and coke DCJcv1 slumped 3.9 percent to 2,353.50 yuan. ($1 = 6.9320 Chinese yuan)