SAO PAULO (Reuters) -Brazilian state-run oil firm Petrobras said on Wednesday that chairman Pietro Mendes has resigned from the role, as well as from his seat on the board of directors.

Mendes is set to become a director at Brazil's oil and gas regulator ANP, after the Senate approved his nomination earlier this week.

In a securities filing, Petrobras noted that under its bylaws, the board can elect a new chairman to serve until the next shareholders' meeting.