Shanghai steel futures gave up early gains to trade slightly lower on Wednesday, as supply concerns eased after China's top steel producing city removed a smog alert.

Benchmark steel rebar on the Shanghai Futures Exchange for May 2020 delivery rose as much as 0.7% before closing down 0.1% at 3,476 yuan ($493.83) per tonne.

Hot-rolled coil, used in cars and home appliances, rose 0.4% to 3,538 yuan per tonne.

China's top steel producing city Tanghan lifted its "orange smog alert" on Tuesday afternoon, government-backed media said, relieving supply pressures amid improving air quality.

Orange is the second-highest level on a three-tiered smog alert system that triggers emergency measures.

The most-traded iron ore futures on the Dalian Commodity Exchange for May 2020 delivery was down 0.9% to 635 yuan per tonne, its third straight session of declines.

China produced 79.25 million tonnes of iron ore in November, up 3.9% from a year earlier, the National Bureau of Statistics said on Tuesday.

Prices for spot cargoes of iron ore with 62% iron content for delivery to China dropped $0.5 to $95 per tonne on Tuesday.

Dalian coking coal, for January 2020 delivery, dipped 0.04% to 1,244 yuan per tonne. Dalian coke, for May 2020 delivery, jumped 1.2% to 1,862 yuan per tonne.