The pair will reveal the gains - equivalent to about $77m a day for both companies - just days after Gordon Brown threatened to call in the Office of Fair Trading to investigate fuel pricing if companies did not pass on the recent drop in the oil price to consumers.
Sunday Times
Anger over BP and Royal Dutch Shell profits
Shell pulls out of its last UK wind farm project
The decision will also anger environmentalists already critical of Shells push into dirty-fuel sources such as Canadas tar sands.