China Life Insurance Company Limited, the nation's largest life insurer, said Thursday that its net profit in the third quarter dropped 46 percent year-on-year, dampened by falling premium revenue and security-trading losses.

Q3 net profits totaled 3.75 billion yuan (586 million U.S. dollars). The profits in the first three quarters this year fell 33 percent from the same period a year ago to 16.72 billion yuan.

China Life's total premium revenue stood at 67.92 billion yuan for the quarter, down 6 percent year-on-year.

Meanwhile, the company's market value dropped 487 million yuan during the period, largely due to the Shanghai Composite Index tumbling 15 percent. Its market value during the third quarter last year gained 515 million yuan.

With its profits highly depending on investments, China Life is more sensitive to the changes in the stock market than its main competitor, Ping An Insurance (Group) Company of China, Ltd.