Sunoco has unveiled plans to sell its oil refineries in Philadelphia and Marcus Hook in Pennsylvania, US.
The firm is conducting a comprehensive strategic review and plans to focus on its more profitable logistics and retail businesses.
Sunoco intends to idle the main processing units at its facilities in July 2012 if a suitable transaction cannot be identified.
The firm expects to record a pre-tax non-cash charge of between $1.9bn and $2.2bn in the third quarter of 2011, related to impairment of the plant and equipment in the refineries.
On selling the refineries or idling of the main processing units, Sunoco will record a pre-tax gain of $2bn related to the liquidation of all of its crude oil and a portion of its refined product inventories.