China Life Insurance Co., Ltd, the country's largest insurer, said on Friday that its preliminary net profit in 2015 grew between five to 10 percent.

The growth was sharply lower than the 30.1-percent growth posted in 2014, with a net profit of 32.2 billion yuan (4.9 billion U.S. dollars).

China Life attributed the profit growth last year to higher investment returns, it said in a statement filed to the Shanghai Stock Exchange.

It cited changes in the discount rate in traditional types of insurances as reason for the decline in profit growth.