SAO PAULO, May 24 (Reuters) - Brazilian state-run oil firm Petrobras said its board of directors on Friday approved the nomination of Magda Chambriard as the company's new Chief Executive.

Chambriard, who was also appointed to a seat on the board, has already taken office in the position, Petrobras said in a securities filing. (Reporting by Peter Frontini; Editing by Gabriel Araujo)