When Zambian President Kenneth Kaunda arrived on Ugandan soil this morning for the first time in 11 years, he immediately dropped to his knees and prayed.

A surprised and obviously moved Milton Obote, the restored president, joined Kaunda on the red-carpeted airport runway in the 15-second silent prayer of thanks for the deliverance of the country from the ruthless dictatorship of Idi Amin.

Thus did Uganda, known as the pearl of Africa until almost a decade of murder and chaos under Amin, return to the family of African nations today as it played host to a four-nation summit of countries from the eastern and southern regions of the continent.

Technically, the four-hour meeting of Presidents Julius Nyerere of Tanzania, Daniel arap Moi of Kenya, Kaunda and Obote was designed to restore some of the unity that Amin helped to destroy.

Obote said after the meeting that the leaders agreed "to establish the political will" to "expand trade and seek new forms of cooperation."

He described the talks as "very cordial, very brotherly," but there was little visible progress in restoring economic ties that could significantly affect the four nations, which are battling serious financial difficulties.

The meeting was long on ceremony and short on substance. In the African context, however, where great store is put on "brotherly" meetings, the very fact of the occasion was of overriding importance.

It was the first time any of the three visiting heads of state had set foot in Uganda in 11 years. There had not been any kind of state visit in six years since Amin played host to the annual summit of the Organization of African Unity in 1975, much to the embarassment of many African leaders who boycotted the meeting.

Despite surface cordiality, it was apparent that there is still a good deal of friction between Kenya and Tanzania, whose hostility has been a key element in the breakdown of East African unity.

Obote, who followed a socialist course before being overthrown by Amin, was instrumental in bringing the two sides together today. Kenya is unabashedly capitalistic while Nyerere has put his country on a socialist path. The growing ideological rift between the two countries finally led in 1977 to the breakup of the East African Community linking Kenya, Tanzania and Uganda -- a grouping that Nairobi increasingly dominated.

The border between Tanzania and Kenya has been closed for four years and there have been sporadic frontier incidents.

Formed during the 1960s, the community had been one of the brightest hopes for African cooperation. At the peak of unity, the three countries shared ownership of air, rail and shipping companies, had one university, one currency and one postal system. Mostly it was the legacy of shared experience under British colonialism.

Today, the leaders spent considerable time discussing the disposal of the assets of the community.

Obote announced that he, Moi and Nyerere would "constitute an authority" to hear reports of concerned ministers of the three countries on the disposal. Such talks at lower levels have failed to produce an agreement over the last four years despite the efforts of an outside mediator.

Nyerere, a close friend of Obote, obviously enjoyed himself, as he was the hero of the occasion. During Amin's rule, Nyerere gave asylum to Obote and 40,000 Tanzanian troops played the key role in driving the dictator out in 1979.

Moi and Obote have never been close because of the Ugandan's former socialist leanings and his friendship with Nyerere. Moi, however, quickly accepted the controversial election of Obote in December and early this month had a separate meeting with the Ugandan leader that apparently led to today's summit.

It is possible that Moi, in response to his gesture, expected more concrete economic benefits from the summit, such as a limited reopening of trade with Tanzania. Many Tanzanian businessmen, however, oppose that since they have established replacement industries for a number of former Kenyan-produced items.