This excerpt taken from the PBR 6-K filed Mar 18, 2005.
(ii) Thermoelectric plants generating energy that belongs to PETROBRAS (commodity price risks)
PETROBRAS had a commitment to supply natural gas for the production of energy at the Thermoelectric Plants Termorio, Termobahia and Ibiritermo, and also to purchase part or all the energy generated by these plants at a price that remunerates invested capital. The Company has third party commitments with the Thermoelectric Plants Três Lagoas, Canoas and Nova Piratininga, involving basically operation and maintenance contracts. During 2004, PETROBRAS adopted measures with a view to substantially reducing its future commitments to these plants.