Insurance broker Austcover has acquired both the retail and wholesale business of public liability specialist Altiora Group for an undisclosed sum to add underwriting services and increase its small-business client base.

Austcover CEO David Ingram told Sunrise Exchange News the deal could limit the company's exposure to market fluctuations.

"Having previously dealt in larger premium clients that are greatly affected in the current insurance market we've purchased a greater volume of smaller premium clients to balance that," he said.

The acquisition of Altiora means Austcover's Sydney-based staff numbers have increased from 12 to 40.

"We were looking to do something in Sydney," Mr Ingram said. "It was a big purchase but these things don't often come along."

Existing Altiora retail and wholesale brands will remain but will be under the control of Austcover directors David Kleinhans, John Berge and Mr Ingram.

Previous Altiora owners the Douglas family will remain with the business for the next four years.

Austcover's combined Sydney and Brisbane operations now employ 95 staff. Six administrative staff left the company following the acquisition.