SAO PAULO, Aug 4 (Reuters) - The controlling shareholders of Brazil-based petrochemical producer Braskem SA are considering moving to a U.S. headquarters as they study options to simplify its ownership structure and improve corporate governance, newspapers reported on Friday.
Braskem is controlled by state oil firm Petroleo Brasileiro SA and engineering group Odebrecht SA, which are in talks to revise their shareholder agreement.
One of the ideas under review in the process is a plan to move Braskem's headquarters to the United States, newspapers Valor Economico and O Estado de S. Paulo wrote, without saying where they got the information.
Estado reported that the possibility of unifying Braskem's multiple share classes was also under review. Additionally, Valor said a dispersed ownership structure and the end of a controlling shareholder accord were under consideration.
Braskem shares rose 3 percent in midday Sao Paulo trading, just shy of an all-time high hit on July 20. New York-listed American depositary receipts rose 4 percent.
Braskem declined to comment. Odebrecht and Petrobras, as the oil company is known, did not immediately respond to questions.
Braskem was at the center of a political corruption scandal involving Odebrecht and Petrobras and pleaded guilty in U.S. court in December to conspiring to violate a foreign bribery law, agreeing to pay a $957 million penalty.
Braskem has also been faced with an investigation in Mexico and a shareholder lawsuit in the United States regarding the scandal, as well as issues with delayed filings in Brazil.
The operator of Sao Paulo's stock exchange warned last month that Braskem could be suspended from Level 1 trading after failing to submit certain financial statements by a deadline. Moody's Investors Service put the company's debt ratings on review for downgrade due to the delay.
Odebrecht owns 50.1 percent of Braskem's common shares and Petrobras owns 47.0 percent. Including preferred shares, they own a combined 74.4 percent stake in the company.
Both Odebrecht and Petrobras are in the middle of major asset sales programs as they seek to reduce debt after financing costs spiked due to the corruption scandal. (Reporting by Ana Mano; Editing by Brad Haynes and Tom Brown)