Federal officials have approved a five-day mission to Cuba to be led by Illinois Governor George Ryan, who will become the first governor to visit the nation since Fidel Castro came to power. Ryan is to leave Saturday with more than 40 legislators, various state officials and representatives of Illinois-based companies, including food manufacturer Archer-Daniels-Midland Corporation and the pharmaceutical maker Baxter International. The approval, granted late Monday by the Treasury Department, comes months after President Clinton loosened restrictions on U.S. contact with the island nation. Trade with Cuba has been embargoed since 1960. Ryan is a first-term Republican who has been opposed to the ban and has called for a trip, a trade mission, with the group planning to deliver $1 million in food, medicine and supplies. He has recently called his trip a humanitarian mission.