Brazil's presidential palace says former President Luiz Inacio Lula da Silva has been named chief of staff to his successor, President Dilma Rousseff.
The move will help Lula avoid possible detention in expanding corruption probes centering on the state-run oil company, Petrobras.
Officials in Lula and Rousseff's Workers' Party say the appointment will help Rousseff fight impeachment proceedings in an unrelated case centered on allegations of fiscal mismanagement.
Chief of staff is the government's No. 2 position, and analysts have said Lula's appointment effectively eclipses Rousseff and makes him the most powerful figure in the government.