The company holds a 60% interest in the Wandoo field (Mitsui 40%) and 20% of the Woollybut field (Agip 65%; Tap Oil 15%).

ExxonMobil acquired its stakes in the two oilfields in 1996 as part of its takeover of Ampol Exploration, with the main production facility coming on stream in 1997, costing around $600 million to develop and with an expected life of 20 years. Wandoo produced about 6.59 million barrels in 2001.

The announcement is the second major sale offering from ExxonMobil this year following the January move to put the company interest in the Cooper-Eromanga Basin gasfield, in South Australia, on the market, which analysts valued at up to $800 million.

The company's key remaining asset in Australia is its 50% stake in Bass Strait, an offshore oil and gas facility, at which the company is also the operator.

ExxonMobil said it would not be entering a tender process but would approach a limited number of companies it thought would be interested in the interests.