Tower Australia is planning to expand its group insurance business and hire up to 100 more staff on the back of signing an insurance deal worth $600 million with AustralianSuper.

"We've got a lot more staff to hire and have started that journey, but now we'll be looking to reorganise and secure a significant number of people," Tower Australia chief executive Jim Minto said.

Minto said Tower Australia had been recruiting key managers over the past six months for the claims business and the group insurance business as well as technology specialists.

"Now we are looking to hire more people such as claims case managers and those that can rehabilitate members," he said.

"You need lots of extra people who can help members when they are unwell and help restore their health and get them back work."

He said despite the size of the AustralianSuper contract, he wanted to preserve service levels for current clients.

"The reality is that we have very good clients and we are looking to build up the entire area of this business. We just see it is as a major opportunity going into the future and we did it based on the conviction that it was an attractive area to be involved in," he said.

Tower Australia has four teams focusing on group insurance, with one being dedicated to AustralianSuper.

"We've spent a lot of time trying to design a very unique service model and I think that was one of the real points of difference. We can really partner with organisations and make a difference," Minto said.

The new three-year insurance agreement will save AustralianSuper members more than $48 million in premiums, with many of the savings being directed into increased levels of cover to address underinsurance.

The new arrangements will come into effect in early 2010.