Nissan Motor Co.'s board, whose lapses in oversight were revealed by the arrest of former Chairman Carlos Ghosn for alleged financial improprieties, has taken on expanded powers.

The board widened the scope of decisions that require its approval and decided on an interim process to set compensation for directors and executives, according to a statement Thursday. Nissan has come under fire for internal rules that provided little oversight over Ghosn, a globe-trotting business icon who once led a rescue of the automaker, in directing his own pay.

Chief Executive Officer Hiroto Saikawa, a former Ghosn protege, has pledged to address corporate governance shortcomings that ensnared the company in the scandal involving the former chairman, who was accused of underreporting his income. The Japanese carmaker is rushing to regain credibility as questions swirl over its relationship with French partner Renault SA and the future of their automotive alliance.