Chief executive Sam Stubbs said they were adopting a quantative, value style of investment and that the company had recruited a number of new staff who were "familiar with managing money this way, they have done it before and very successfully."

"It's actually very simple what we're doing," he said.

Tower would retain two of the seven external managers and he said the investment style they would be adopting, "is very much something the likes of Benjamin Graham and Warren Buffett would instantly recognise."

Stubbs declined to name the managers in question as they had not all been informed, however he did say one being retained was a particularly strong performer and the other was in emerging markets.

He said the decision to retain the emerging markets manager was due to that sectors increased geographical complexity and need for very high quality data, "so where we can't do that ourselves we'll continue to outsource."

He said the changes had been eight months in the planning and he was happy with the back testing and screening that had taken place, promising Tower was positioning itself to provide strong, long-term value returns.

"We're so confident of this we'll be investing our own money and shareholders funds in these strategies, so we'll be very much eating our own cooking on this," he said.

"This will have completed our review of how we're managing money so we now know we have very comfortable, long term, value orientated strategies on fixed income, property and equities, we're ready to go and I think you'll see this is the way Tower will be managing money for a long time now."