Dominique Strauss-Kahn resigned Thursday as head of the International Monetary Fund, saying he did so with "infinite sadness" but must focus entirely on clearing his name of sexual assault charges. The move came as lawyers for Strauss-Kahn prepared to enter a new bail petition Thursday to free him from jail and his resignation promised to kick off an IMF leadership succession battle between emerging economies and Western nations that have long dominated the world body. Duration: 01:12.