* Mills churned out more even as winter curbs in place
* Pace of output will raise concerns about oversupply
* Winter heating season ends on Thursday
* Jan-Feb output +5.9 pct on year - stats bureau
* Daily output 2.32 million tonnes (Updates throughout)
BEIJING, March 14 (Reuters) - China’s daily steel output rose in January and February as mills in the world’s top producer raced to take advantage of high prices, even as worries mount about a growing surplus and slowing demand from the construction sector.
The strong output data on Wednesday helped push prices lower in Shanghai, with rebar construction steel futures hitting their lowest in almost four months, extending their longest losing streak since last summer.
The production rise came despite Beijing’s stringent crackdown on heavy manufacturing in 28 of its smoggiest cities as part of its war on winter smog. Those curbs will be lifted in most regions on Thursday, which marks the end of the four-month winter heating seaon.
The data will likely draw international scrutiny after U.S. President Donald Trump this month slapped hefty import duties on steel, aimed at curbing Chinese shipments.
Global producers have for years accused China of exporting its excess metal at bargain prices after huge capacity expansions.
Chinese mills produced 136.82 million tonnes of crude steel in January and February, up 5.9 percent from a year earlier, data from the National Bureau of Statistics (NBS) showed.
The NBS only provided combined output figures for January and February due to the distortive effects of the Lunar New Year holiday that sees much of China shut down for a week.
Daily output was 2.32 million tonnes, up 7.4 percent from December and up more than 5 percent on the same two months last year, according to Reuters calculations.
It was the highest daily rate since October, before the winter heating season started in November when strict output curbs came into force, and the fastest pace for the first two months of the year on Reuters’ records going back to 2015.
China’s push to close older, polluting steel mills drove up local steel prices, encouraging other producers to boost output in anticipation of a seasonal pickup in demand after the holiday period, despite Beijing’s output curbs, analysts said.
Qiu Yuecheng, analyst at steel trading platform Xiben New Line E-commerce in Shanghai, said the output was higher than expected.
“Mills are ramping up to production driven by solid profits,” said Qiu.
Still, concerns are growing that the post-holiday demand has not materialised.
Stockpiles of rebar SH-TOT-RBARINV hit their highest since 2013 this week and rebar prices have fallen 7 percent so far this month, putting them on track for the biggest monthly fall in 18 months.
Reporting by Josephine Mason and Ruby Lian; editing by Richard Pullin