Sanlam's Bellville head office in the Western Cape. Picture: David Ritchie.

Johannesburg - South Africa's biggest insurer, Sanlam, reported a 23 percent jump in earnings for the first four months of the year on Wednesday after booking increased new business volumes and higher returns from investment services.

The company established nearly a century ago said new business increased 21 percent to 59 billion rand while earnings from financial services improved by 40 percent.

Sanlam said on Tuesday it had concluded an agreement to purchase a 63 percent stake in Soras Group, Rwanda's biggest life and non-life insurer.

The $24.3 million purchase is its first foray into the country.

Sanlam has businesses in 16 countries including 11 other African countries and has set aside $370 million for emerging market acquisitions this year.

Its shares fell 0.28 percent to 60.20 rand as at 14:19 SA time. - Reuters