Revenues from Egypt's Suez Canal slipped to $435.3 million in September, down from 2.5 per cent the month before, state figures showed on Wednesday. August revenues from the Canal were $446.6 million, in September 2011 they were $438.3 million. The waterway is a vital source of foreign currency in Egypt, along with tourism, oil and gas exports and remittances from Egyptians overseas.