By Sabrina Valle HOUSTON (Reuters) – Petroleo Brasileiro SA chairman Admiral Eduardo Bacellar Leal Ferreira told Reuters on Saturday he plans to step down from the position, with oil executive Rodolfo Landim seen as his possible successor, according to two sources familiar with the matter. “Petrobras chairman is a 24-hour job and I want to spend more time with my family,” Ferreira said, adding he has two grown children living outside of Brazil. Ferreira declined to comment further. His decision comes as Petrobras, as the Rio de Janeiro-based company is known, faces pressure from investors to r…