The figure also represented the largest monthly decrease for the past five months, reported Xinhua.
In the first eight months, profits for industrial firms fell 3.1% from a year earlier to 3.06 trillion yuan, 0.4 percentage points greater than the decrease for the first seven months.
Profits for state-run industrial enterprises, joint ventures and overseas-invested companies dropped, while private and collectively-owned firms recorded profit gains, the figures showed.
State-run firms saw profits decline 12.7% year on year in the first eight months. Private sector profits grew 15.1%.
Profits for foreign-funded companies and those from Hong Kong, Macao and Taiwan fell 12.7% year on year to 703.4 billion yuan.
Out of 41 industry categories, 24 reported year-on-year profit gains, while 16 saw profits fall and one saw a loss, the figures showed.