China's listed steel firms reported a surge in earnings in the first half of this year amid continued government efforts to cut overcapacity in the sector.

Steel companies listed on the Shanghai Stock Exchange reported combined profits of 29.6 billion yuan ($4.34 billion) in H1, up 134 percent year-on-year, data from the exchange showed.

Total revenue of these companies reached 426.5 billion yuan, up 15 percent year-on-year.

The rise came as authorities continued efforts to cut excess capacity in the industry as part of the country's supply-side structural reform.

In the first seven months of 2018, China cut outdated crude steel capacity by 24.7 million metric tons, completing more than 80 percent of this year's capacity-cut target of 30 million tons, according to the National Development and Reform Commission.