FORMER US OFFICIAL IN SEOUL AFTER N. KOREA VISIT

Former United States State Department official Gaston Sigur arrived Sunday to brief South Korean leaders on a visit last week to communist North Korea. Mr. Sigur was one of the most prominent Americans to visit Pyongyang, and Seoul newspapers said he met a number of senior North Korean officials to discuss ways to ease tensions on the Korean Peninsula.

Sigur, Assistant Secretary of State for Asian and Pacific Affairs under President Reagan, told reporters the talks were ``frank, candid and constructive.'' He gave no other details.