This excerpt taken from the PBR 6-K filed Mar 7, 2008.
Statement of Other Operating Revenues (Expenses) - 2006
Part of the expenses associated with idle thermoelectric plants were allocated to COGS, given that such expenses are linked to energy sales which are in turn tied to the capacity available for sale, independently of the volume effectively generated.
In order to unify the criterion for the allocation of safety, health and environmental expenses, we opted to allocate these expenses in their entirety to other operating income (expenses).
In order to maintain comparability between the periods, we are presenting the previous statements in accordance with the new criteria above.