The profits of China's three leading insurance companies all dropped sharply in the first half as a weak capital market dragged down investment returns.

China Life Insurance Co, China's largest insurer, released a statement on Sunday that its profit in the first half of the year may fall 65 percent to 70 percent from a year earlier. It attributed the forecast to lower investment income and changes in the assumed discount-rate required for reserves for traditional insurance contracts.

China Pacific Insurance Holdings Co also projected a first-half profit drop of 46 percent, according to its statement on Sunday, for the same reasons as China Life.