RIO DE JANEIRO (AP) -- Brazilian state-run oil giant Petrobras has sworn in its first woman chief executive.
Maria das Gracas Silva Foster took over the top spot a ceremony Monday in Rio de Janeiro attended by Brazilian President Dilma Rousseff.
During her speech, Foster underscored that she is the first woman to head any of the world's oil majors and stressed she was prepared to meet the challenge.
Foster, who formerly ran Petrobras' gas and energy sector, takes over from outgoing CEO Sergio Gabrielli.
Under Gabrielli, Petroleo Brasileiro SA made massive discoveries off Brazil's southeastern coast, which likely hold more than 50 billion barrels of oil.
Foster promised "continuity" in her leadership style.

