JOHANNESBURG, South Africa (AP) _ The government said today it has withdrawn its decision to expel Los Angeles Times correspondent Michael Parks from South Africa.

Minister of Home Affairs Stoffel Botha said Parks' work permit has been extended for three months. Foreign journalists working in South Africa usually receive work permits for three- or six-month periods.

Parks, 43, has been in South Africa since mid-1984. The government announced Dec. 9 that it would not renew his work permit, which had expired in September, and told him to leave the country by Dec. 31. No reason for the action was given.

Later the deadline was extended until the end of January to allow Los Angeles Times Editor William F. Thomas and Foreign Editor Alvin Shuster to come to South Africa to appeal the decision.

Botha met Tuesday in Cape Town with Parks and the two editors.

''In view of assurances and undertakings received during these discussions the minister agreed to renew the temporary work permit of Mr. Parks for a further period of three months,'' a ministry statement said. It did not elaborate.

Thomas issued a statement saying, ''We are pleased that the minister has extended Mr. Parks' work permit. The assurances I gave the minister were that the Times will continue to strive for the fair and balanced coverage it promised when the South African government allowed it to open a bureau in Johannesburg 15 years ago.''

Park's previous posts included Peking, Hong Kong, Cairo, Beirut, Moscow and Saigon.

Last Saturday, New York Times correspondent Alan Cowell left the country after the government refused to renew his work permit. It also refused to grant a visa to his designated successor, Serge Schmemann.

Officials refused a request from New York Times editors to come to South Africa to appeal the expulsion order.

Cowell was the fifth foreign journalist expelled from the country since June 1986.