Profits at China's state-owned non-financial enterprises (SOEs) fell 10.9 percent in the first two months of 2012 from the same period a year earlier, the Ministry of Finance said.
It marked the first decline since November 2009.
SOEs, defined as those controlled by Beijing and local governments, had combined profit of 363.5 billion yuan ($57.5 billion) in the January-February period, according to a statement on the ministry's website (www.mof.gov.cn) posted late on Monday.
Firms in the steel, petrochemical, property construction and machinery industries suffered falling profits, while tobacco and telecoms companies enjoyed handsome earnings increases, it said.
In all of 2011, these companies had a profit rise of 12.8 percent, slowing from a 38 percent jump in 2010, as weakening external demand took a toll on the world's No 2 economy.
The National Bureau of Statistics is scheduled to announce profits of all Chinese industrial firms next week.
Other economic indicators published in the past two weeks showed that China's economy was on course for a soft landing, revealing ample room for Beijing to loosen policy further to support growth.
