This excerpt taken from the PBR 6-K filed Aug 13, 2008.
The quarter-over-quarter improvement was due to the following factors:
The increase in average domestic oil product prices, led by gasoline and diesel in the domestic market;
Higher sales volume in Brazil and abroad;
The sale, in the 2Q-2008, of inventories acquired at a lower cost in the previous quarter;
Gains from the change in holdings provoked by the corporate restructuring of Quattor Participações (R$ 409 million).
These effects were partially offset by higher average oil acquisition/transfer costs and the increase in oil product import costs.
The year-on-year improvement in the first-half Gas and Energy result was due to the wider gas sales margin and the increase in electricity sales volume.
These effects were partially offset by contractual fines and charges related to natural gas supply (R$ 295 million).
This excerpt taken from the PBR 6-K filed Nov 21, 2007.
(A free translation of the original report in Portuguese)