SAO PAULO--Iberdrola SA (IBDRY, IBE.MC), Banco do Brasil SA (BDORY, BBAS3.BR) and pension fund Previ, the controlling shareholders of Brazil utility Neoenergia (GNAN3B.SM), said Tuesday they had no plans to "significantly" alter their stakes in the company.

Iberdrola had reportedly been seeking buyers for all or part of its 39% stake in the Brazilian electricity generation, transmission and distribution company. According to a report earlier this month, rules governing pension funds would also force Previ, which has a 49% stake in Neoenergia, to reduce its holding to 25%. A separate report said Previ wanted to buy out its Spanish partner to head off a possible sale to Chinese rivals.

But the controlling shareholders said in a regulatory filing Tuesday that, after a period of reviewing possible changes in the controlling bloc, the existing shareholders "decided to maintain the current shareholder structure with the intent of assuring the maintenance of the partnership on a solid and economically favorable base favorable to all involved."

However, the companies said they may modify the shareholding structure to allow Iberdrola to adapt to International Financial Reporting Standards accounting rules, but didn't clarify what those changes might entail.

Brazil's power industry has seen a number of ownership changes in recent months, as European companies, often tied to their respective governments, sold stakes to bolster their balance sheets. EDP-Energias de Portugal SA (EDPFY, EDP.LB), for example, sold a controlling stake to China's Three Gorges Corp. Meanwhile, financing difficulties at some distributors have led to consolidation in that industry, and growing demand for new generation and transmission sources has led to mergers and acquisitions in the sector.

Write to Paulo Winterstein at paulo.winterstein@dowjones.com.

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