SEOUL, NOV. 30 (MONDAY) -- A Korean Air passenger jet with 115 persons aboard disappeared over Southeast Asia yesterday and was feared to have crashed while traveling here from the Middle East.

The jet was over Burma, en route from Abu Dhabi, in the United Arab Emirates, to Bangkok for a refueling stop, when air traffic controllers lost contact, airline and South Korean government officials said today.

If the plane crashed, it would be the second airline disaster in two days. A South African Airways jumbo jet carrying 160 crashed Saturday off the Indian Ocean island of Mauritius, killing all aboard.

The Korean plane, a four-engine Boeing 707, was believed to have crashed in a dense jungle area near the Thailand-Burma border.

{A Thai government radio operator reported later that the crew of a Thai Border Patrol Police helicopter had spotted the wreckage of an aircraft, that could be that of the KAL jet, in the Thai border province of Kanchanaburi, about 125 miles northwest of Bangkok, United Press International reported from the Thai capital.

{The searchers reported seeing no sign of life near the wreckage, but police said a ground party was dispatched to the site.}

Officials did not rule out the possibility that the aircraft had been hijacked or otherwise targeted by terrorists.

Burmese government officials also conducted ground and air searches of the border area but said they found no signs of a crash. Korean television reported this morning that a team of 21 government and airline investigators, including KAL chairman Cho Chong Hoon, left today for Bangkok.

Concerns about possible terrorist action were prompted by the arrest by Japanese police last week of Osamu Maruoka, a leader of the Red Army terrorist group. At the time of his arrest in Tokyo, he had a Dec. 7 plane ticket for Seoul in his possession.

Japanese police said they suspected that the long-dormant group was plotting terrorist actions against South Korea to disrupt the presidential elections scheduled far Dec. 16 or the Summer Olympics in Seoul, which are to be held here next September.

Korean officials said this morning that they are investigating the possibility of the Red Army's involvement in the jet's disappearance and are working closely with the Japanese police.

The plane's disappearance over Burma triggered unhappy memories here because four South Korean Cabinet members were killed in a bomb attack in Rangoon, the Burmese capital, in October 1983. Burmese officials blamed North Korea.

KAL pilots are mostly retired Air Force personnel with a reputation for technical skill, but the privately run airline has been involved in two fatal incidents.

In September 1983, KAL flight 007 from Anchorage, Alaska, to Seoul was shot down over Sakhalin Island in the Soviet Union and all 269 aboard died. Moscow claimed the plane was on a spy mission, a charge that the South Koreans and the United States denied.

In 1978 the Soviets forced down a KAL plane near Murmansk and two passengers were killed in a midair shootout.

KAL Flight 858 that disappeared yesterday took off from the Iraqi capital of Baghdad and made a stopover in Abu Dhabi, where 11 of the passengers boarded. Korean officials said all but two of the 95 passengers and 20 crew members were Korean, mostly workers on construction projects in the Middle East. They said the other two passengers were Lebanese and Indian.

Among the passengers were the South Korean consul general in Baghdad, Kang Suk Sae, and his wife. KAL officials also said two children were on the plane.

KAL services Middle Eastern capitals, where South Korean construction firms have many projects.

The plane had been scheduled to land at Seoul's Kimpo Airport at 8:40 p.m. Sunday (6:40 a.m. EST Sunday).

According to television and news agency reports here, the plane, while flying near Rangoon, made routine contact with Bangkok 40 minutes before it was due to land there at 2:40 p.m. The crew did not signal that anything was unusual at the time.

"We expect to arrive at Bangkok on schedule," the pilot told the Bangkok airport control tower in his last contact, according to KAL executive director Lee Kun Soo.

The radio message was received while the jet was 290 miles west of Bangkok and about 154 miles south of Rangoon, Lee said. It was at an altitude of about 37,000 feet when it made its last radio contact.

Burmese officials were quoted yesterday as saying the plane had made routine contact with the Rangoon airport control tower before entering Burmese air space.