An Interim Council of Ministers, assisted by an Interim Economic Committee of officials, was subsequently set up to negotiate the treaty and initiate programmes on economic co-operation, pending the completion of negotiations on thetreaty.
In 1978, at a meeting of Ministers of Trade, Finance and Planning in Lusaka, the creation of a sub-regional economic community was recommended, beginning with a sub-regional preferential trade area which would be gradually upgraded over a ten-year period to a common market until the community had been established. To this end, the meeting adopted the "Lusaka Declaration of Intent and Commitment to the Establishment of a Preferential Trade Area for Eastern and Southern Africa" (PTA) and created an Inter-governmental Negotiating Team on the Treaty for the establishment of the PTA. The meeting also agreed on an indicative time-table for the work of the Intergovernmental Negotiating Team.
After the preparatory work had been completed a meeting of Heads of State and Government was convened in Lusaka on 21st December 1981 at which the Treaty establishing the PTA was signed. The Treaty came into forceon 30th September 1982 after it