Ethiopia Base and 2 Towns Said to Fall to Rebels. By JANE PERLEZ, Special to The New York Times Published: December 28, 1989

Ethiopia Base and 2 Towns Said to Fall to Rebels

By JANE PERLEZ, Special to The New York Times

Published: December 28, 1989

In a significant setback for the Ethiopian Government, Tigrean rebels have captured a major military base and two other towns, the rebels and Western diplomats in Addis Ababa said today.

Fighting escalated in the Ethiopian civil war last week, after talks between the Tigrean People's Liberation Front and the Government ended in Rome. The talks made some progress on procedural issues but were obstreperous in tone and are not scheduled to begin again until March, diplomats said.

The Tigrean military gains were in two provinces, Gondar and Shoa, the latter being particularly significant because it is the province that includes Addis Ababa.

The rebels said they had overrun Debra Tabor, a military base near the city of Gondar. The base is thought to have about 10,000 Ethiopian troops. If the base remained in rebel hands, the Tigrean rebel group would have direct access to Gondar, an ancient Ethiopian city famed for its many churches. An attack on Gondar by the rebels would represent a major psychological as well as material blow to the Government of Col. Mengistu Haile Mariam. Soviet-Trained Unit Defeated

In northern Shoa, the rebels said they overran Rabel and Mahel Meda, where diplomats estimated the rebels either captured or killed about 1,500 troops.

The rebels, a group based in the province of Tigre, is one of several insurgencies battling the 15-year-old Marxist-Leninist Government. For the last 14 years, it has been seeking to overthrow Colonel Mengistu and replace him with its more rigid version of Marxism-Leninism.

The Tigrean rebels have made remarkable military gains this year, successfully driving the flagging Ethiopian Army out of the province of Tigre. Several months ago, the crack, Russian-trained 102d Airborne Division was rushed to the Tigrean front, only to be defeated.

The Government is also hampered because Soviet military advisers have been withdrawn from key military installations as part of the general downgrading by the Soviets of the importance of Ethiopia. Albania as Model for Ethiopia

But the Tigrean rebels have not been doing so well on the political front. In a recent interview with the BBC, Haile Tilahun, a political commissar of the Ethiopian People's Revolutionary Democratic Movement, which is part of the Tigrean rebel group, described President Mikhail S. Gorbachev of the Soviet Union as a revisionist. He held up Albania as the model for the Ethiopia that his movement would strive toward.

The Tigrean rebels have made similar statements on their radio programs, which residents of Addis Ababa can monitor. In the last month, Colonel Mengistu, one of the most hard-line Marxist rulers left in the world, has been able to make much of the Tigrean rebels' political intentions, to his own advantage. Recent propaganda in the state-run press has implied that if Ethiopians - the poorest people in the world, according to World Bank statistics - think they are badly off now, they would be worse off under the Tigrean rebels.

Colonel Mengistu, whose popularity was thought to be at an all-time low two months ago, when diplomats said there were two assassination attempts against him, has been able to shore himself up because of the threat of the Tigrean rebels, several diplomats and Ethiopians said. Ethiopians, who tend to be very nationalistic, have responded to the calls by Colonel Mengistu in the last month that the rebels should not be allowed to destroy Ethiopia and its Amharic culture, they said.

Residents in Addis Ababa say they expected a counteroffensive by the Ethopian Army soon. A half-million-strong peasant army is being formed and residents report seeing training on the outskirts of the city, with conscripts being taught how to march and given target practice. Eritrean-Rebel Offensive Seen

At the same time that the Government is said to be preparing for a counteroffensive, the other major rebel group, the Eritrean People's Liberation Front, which is also Marxist, is believed to be preparing for renewed fighting.

That group is expected to make a decision at its Central Committee meeting, now in session, on when and whether to attack the remaining part of the province of Eriteria they do not yet hold. The front, which is seeking secession for Eritrea from Ethiopia, holds about two-thirds of the province.