Major Chinese industrial firms posted enlarged declines in their profits in July, official data showed Monday.

Profits for major industrial companies, or those with annual revenues of more than 20 million yuan ($3.2 million), slipped 5.4 percent year-on-year to 366.8 billion yuan in July, the National Bureau of Statistics said in a statement.

The decline was larger than the 1.7-percent year-on-year drop in industrial profits seen in June and the 5.3-percent year-on-year drop seen in May.

In the first seven months, profits for industrial firms fell 2.7 percent from the same period last year to 2.68 trillion yuan, 0.5 percentage points greater than the decrease for the first six months.

In the first seven months, state-owned and state-controlled industrial enterprises saw their profits fall 12.2 percent from a year earlier to 784.7 billion yuan, while private companies' profits grew 15.5 percent to 818.7 billion yuan, according to NBS data.

During the period, foreign-funded enterprises and those invested by businesses from Hong Kong, Macao and Taiwan saw profits drop 12.6 percent year on year to 609 billion yuan. Out of 41 industry categories, 25 reported a year-on-year increase in profits, while 15 saw profits fall and one dropped to a loss, the data showed.

The ferrous metal sector was hit the hardest, with profits slumping by 60.8 percent year-on-year. The chemical raw materials and product manufacturing industries suffered a 21.3-percent drop in profits.

The oil and gas exploration industry witnessed a 2.1-percent drop in profits, while oil refining, coking and nuclear fuel processing companies saw profits turn into losses. Profits in the power and heat generation sector, however, increased 29.3 percent, according to the statement.