By Min Zhang and Shivani Singh

BEIJING (Reuters) -China’s crude steel output hit an all-time high in April, despite the government’s pledge to curb annual production to reduce pollution as well as increasing costs from raw materials.

With mills cranking up production fuelled by strong profits, the world’s top steel producer churned out 97.85 million tonnes of the metal last month, data from the National Bureau of Statistics (NBS) showed on Monday.

That was up 4.1% from March and well above output of 85.03 million tonnes in April 2020.

Average daily output in April rose 7.5% from March to 3.26 million tonnes, also a historical high, Reuters calculations based on official data showed.

Steel production in China had been rising for two straight months, even though Beijing has repeatedly vowed to ensure the country’s full-year output remains below the 1.065 billion tonnes produced last year.

Improving profit margins, stoked by rosy demand and sky-rocketing steel prices, boosted mills’ appetite for production.

“Besides increasing output at long-processing mills that are not subject to curbs, production at electric arc furnaces also gained,” said Liu Xinwei, chief researcher with Sublime China Information.

Futures prices for construction rebar and hot rolled coils have jumped 32% and 38% so far this year, respectively. Spot market prices also broke above 6,000 yuan ($931.47) a tonne.

Output at major mills has been running at much higher levels so far in 2021 compared with the same period in the past four years, data from the China Iron and Steel Association showed.

In the first four months of the year, China produced 374.56 million tonnes of crude steel, up 16% on the same period last year, the NBS data showed.

(Reporting by Min Zhang and Shivani Singh; Editing by Neil Fullick and Kenneth Maxwell)