Australian finance, insurance, and banking corporation Suncorp-Metway (ASX:SUN) is in line for a windfall of up to $125 million from the sale of its holdings in two car insurance joint ventures, as it attempts to simplify its insurance business and increase returns.

The Brisbane-based company earlier this year announced the sale of its 50 per cent stakes in joint ventures with RACQ in Queensland and RAA in South Australia back to the respective motoring organisations.

The decision is part of efforts by chief executive Patrick Snowball to improve the insurance business, which he has called ''over-engineered and complicated''.

An appraisal of the two ventures estimated the shares at $348 million. After the sale, Suncorp anticipates a post-tax windfall of $110 to 125 million. The valuation of the holdings indicates the two ventures generated about $30 million each year for Suncorp.

Before the valuation of the business was revealed, analysts were tipping Suncorp to hand over a full-year profit of $570 million. This compares with the $348 million last year, which was slammed by unsatisfactory insurance returns and heavy write-downs across its banking arm.

Suncorp claims the sale of the shareholdings would not affect its ability to compete in either market through its own insurance brands, which include AAMI and GIO.