South Korean President Chun Doo Hwan approved a new constitution endorsed by voters in a referendum Tuesday. The new charter, designed to ensure full democracy, provides for direct election of the president instead of selection by an electoral college. Nearly 1,300 Roman Catholic clergymen and lay people said they have formed an election watchdog body to guard against election-rigging. Korean newspapers reported that the government is considering setting Dec. 15 as the election date. Chun will step down Feb. 24 after seven years in office.