South Korea's Cabinet resigned today, removing the last vestige of civilian control from the government of this troubled nation.

With vast powers to arrest without warrant and to prohibit any political dissent, the military now is in a position to dictate a new form of government, probably a military council dominated by Army leaders and others acceptable to the group of generals running the country under martial law.

The open return of military control in South Korea follows a period of challenge by students and others.

While the Cabinet's formal resignation was announced today, the beginning of the end for the civilian government came Saturday in a building packed with troops and sealed from any communication with the outside world.

Troops encircled the capitol compound when the Cabinet arrived Saturday night. Telephone lines had been disconnected. Inside the capitol, more troops lined the corridors as the ministers filed in.

Education Minister Kim Ok Gill recalled in an interview today what happened then. Prime Minister Shin Hyon Hwack rapped his gavel to call the meeting to order. Defense Minister Choo Young Bok read a brief statement that said martial law should be expanded because of a threat from communist North Korea. The prime minister hit his gavel again and the meeting was over. All ministers signed the statement and left.

"There was not a single debate," Kim said. "We just kept our mouths quiet. It all lasted two or three miniutes."

The statement was in effect the Cabinet's death warrant, handing the military vast new powers to arrest without warrant and to prohibit any political dissent. The final act was the government announcement of the resignations today, which left the military in open, undisputed control.

A government spokesman said the Cabinet resigned as a gesture to take responsibility for the troubles that led to the military takeover last weekend. r

President Choi Kyu Hah is expected to announce some form of new government Thursday, a spokesman said.

Choi Kyung Nok, a retired general, emerged as a likely candidate to nominally head whatever government is imposed. He is a former Army chief of staff and served as ambassador to Mexico and Britain.

The Cabinet's resignation was announced over radio stations at 4 p.m. by the govenment's information minister amid signs that its departure was not voluntary. At the time of the announcement, Kim was giving an interview in which she said she had not made up her mind whether to resign.

The resignations ended a period in which the already weak Cabinet had tried hard to achieve a delicate balance between the military and dissident and opposition leaders. Kim's version of the final days indicates her colleagues gave her more support for a peaceful transistion to democracy than outsiders had believed.

She was the moderate who tried to make piecemeal changes, giving gradual concessions to students and opposition politicians and moving slowly toward constitutional reform and new elections.

"I thought we could make it going step by step," she said today, in her first public interview since the Cabinet handed over power. She disclosed that she had strong support from the prime minister, the defense minister, and others whom outsiders suspected had followed the military hard line.

Even President Choi joined a small group of ministers planning to make concessions last week when thousands of students demonstrated on Seoul's streets, she said. They agreed to cancel public hearings on the government's draft of the constitutional amendment -- at the time a key concession to the opposition, which objected to the government officials promulgating amendments. More concessions were expected.

It also appeared, Kim said, that the student demonstrations were over. By Saturday night, she said, there had been no protests for two days and students had settled back to wait and see what the government would do.

Kim said no one discussed future arrests at the meeting. There was no discussion of the extent to which martial law would be applied, with dozens of arrests to come in the next few days and the closing of the National Assembly, she added.

Kim refused to characterize the atmosphere in the Cabinet meeting, with troops outside in the corridors but she agreed that some members may have kept silient because they were frightened.

The reality became apparent two hours after the meeting when troops knocked on her door and asked for her brother, Kim Dong Gill, who was vice president of Yonsei University. He was away for a speaking engagement, so they left.

Her brother, a prominent dissident who was jailed for a year under the government of slain president Park Chung Hee, was seized in a provincial hotel at 5 a.m. the following morning and has not been heard from since.