* More mills to halt operation near year-end -analysts
* Tangshan saw PM2.5 up 46.8 pct in Nov from last year
* China Q4 business confidence index lowest since Q2 2017 -c.bank survey (Update closing prices)
BEIJING, Dec 25 (Reuters) - Dalian coke futures fell nearly 6 percent on Tuesday to their lowest in three-weeks, hit by concerns over waning demand as more steel mills halt operations for maintenance amid stringent environmental measures.
Cities in northern China are scrambling to step up anti-pollution measures, including asking industrial plants to cut additional output, to ensure they meet the 2018 air quality targets.
Top steelmaking province Hebei’s average concentration of lung-damaging small particulate matter, known as PM2.5, in all 11 cities in the region rose drastically in November compared to the same month last year, according to a statement from the Hebei Environment Protection Bureau on Monday.
The city of Tangshan, accounting for more than 11 percent of China’s total steel output in 2017, saw its PM2.5 reading reach 91 micrograms per cubic metre last month, up 46.8 percent from November last year, the Hebei document said.
“With local authorities tightening anti-pollution measures, more steel mills have scheduled to do maintenance toward the end of the year, which dampens demand for the steelmaking raw material,” said analysts from CITIC Futures in a note in Mandarin.
The most-active coke futures for May delivery on the Dalian Commodity Exchange slumped as much as 5.8 percent, the biggest intra-day loss in a month, to 1,866 yuan ($270.99) a tonne. It closed down 4.7 percent at 1,888.50 yuan.
The fall also came following a broader sell-off across risk assets from stocks to metals as a gloomy outlook for the global economy persisted.
Business confidence among entrepreneurs in China worsened in the fourth quarter compared with the previous one, and was at the lowest since the second quarter of 2017, according to a survey by the People’s Bank of China published on Monday.
Shanghai benchmark rebar futures fell 1.9 percent to 3,398 yuan a tonne after touching its lowest level in four weeks at 3,357 yuan in early trading on Tuesday.
Dalian iron ore prices dropped 0.7 percent to 486 yuan a tonne, while coking coal contract settled down 2.3 percent to 1,168 yuan.
China Minmetals Corp said on Monday it will buy 2.04 million tonnes of Pilbara Blend lump ore from Australian miner Rio Tinto Ltd at a price of around 999.6 million yuan in 2019. That puts the cost of each tonnage of ore at about 490 yuan a tonne. ($1 = 6.8859 Chinese yuan renminbi) (Reporting by Muyu Xu and Ryan Woo; Editing by Muralikumar Anantharaman and Christian Schmollinger)