Liberty, majority owned by Standard Bank Group [JSE:SBK], said basic headline earnings per share totalled 440.2c in the six months to end-June, compared with 371.9c a year ago. Headline earnings, the main profit gauge in South Africa, exclude some one-time items.
Liberty warned that volatility in South Africa's investment market would likely affect returns.
The insurer swung to a profit a year ago after a recession led to lapses on policy payments.
Liberty's rival Sanlam [JSE:SLM] has warned that the business environment remains challenging and that it is unlikely to book strong earnings growth similar to those achieved in the latter part of 2010.
Liberty shares have gained 1% so far this year, compared with a 0.9% drop in Johannesburg's index of life insurance companies .