China's steel industry is a big cause for concern in the fourth quarter due to shrinking demand and heavy losses, according to an industry official.

The fears were outlined by Huang Libin, an official from the Ministry of Industry and Information Technology, in an interview with China National Radio.

"The steel sector's performance has been bad since the beginning of the year," Huang said. "Their revenues are falling and demand remains weak." The entire steel sector is now operating at a loss and struggling with problems of oversupply and a broader economic slowdown, he said.

MIIT data show that 45 percent of the country's steel companies suffered losses in the first nine months of 2012.

According to figures from the National Development and Reform Commission, 80 major steel firms reported a combined loss of 5.53 billion yuan ($877.78 million) in the January-September period.

Angang Steel Co Ltd and five other steel companies were listed among the top 10 A-share companies in terms of losses in the first three quarters, according to the NDRC.

China's crude steel output grew 1.7 percent year-on-year from January to September to reach 542.34 million tons, 9 percentage points less than the same period last year, NDRC data indicate.