(AGI) Lagos, June 24 - A four-seater plane has vanished betweenNigeria and Gabon according to aviation sources in Cameroon.Owned by US Global Aviation, the plane left Kano at 6 p.m. onMonday for Libreville in Gabon, where it was expected to landat 11 p.m. after stopping in Douala, Cameroon. Only the pilotwas on board and the plane never arrived in Douala aftercontacted the control tower in Mongo. The plane has not yetbeen found. . .