(Adds details on subsalt rule, process of correcting it, comments from Cunha, stock action)
RIO DE JANEIRO, June 26 (Reuters) - Brazil's president of the lower house, Eduardo Cunha, said on Friday that a requirement in the national oil law that state-run oil producer Petroleo Brasileiro SA, known as Petrobras, participate in all subsalt exploration and production blocks will be "corrected."
Under the current legislation in Brazil, Petrobras must hold at least a 30 percent stake and function as operator in any new subsalt oil block that is auctioned by the government.
This requirement has put undue pressure on the company's capital. Petrobras has been struggling to meet its production goals and manage its growing debt load, even before it became the center of Brazil's biggest corruption scandal in history.
Under an earlier law in Brazil, Petrobras was not required to be a partner or operator in subsalt fields, or rock formations beneath layers of salt that may contain oil.
"We were wrong when we changed the oil law from a concession model to a production sharing regime," Cunha said. "The requirement that Petrobras (hold 30 percent of all subsalt blocks) will be corrected. As for the change in the (overall) oil regime, I don't know."
Petrobras shares rose after Cunha's comments and are trading up 4 percent at 13.11 reais on the Sao Paulo stock exchange.
Cunha said the Senate should vote next week on a bill to remove the requirement that Petrobras be at least a 30 percent partner in all subsalt fields, after which the bill would go to the lower house.
The congressman said he was also in favor of eliminating the requirement that Petrobras be the operator in all subsalt fields as well, but that it was not for him to decide.
"If it were my choice, this would be eliminated too," Cunha said. "Changing the production sharing regime will be difficult but removing the 30 percent requirement, yes. That is possible." (Reporting by Rodrigo Viga Gaier; Writing by Reese Ewing; Editing by Andrew Hay)