LUANDA (Reuters) - Angola said on Wednesday it was legalising the former rebel movement UNITA in the first major step towards sealing a long delayed peace accord in the war-ravaged oil and diamond-rich southern African nation. "We (government) issued a declaration half-an-hour ago and it will be formally promulgated on national radio at 1.00 p.m. (1200 GMT)," Higino Carneiro, the government's top negotiator, told Reuters. Carneiro said technical details of the special status for veteran UNITA leader Jonas Savimbi were still being worked out. The government declaration officially legalises UNITA as the main opposition party in Angola. It was widely expected to follow UNITA's formal declaration last Friday of military demobilisation -- a requirement for officially ending Africa's longest running civil war. Demobilisation was one of the conditions set by the United Nations and the Angolan government for concluding the long-delayed peace settlement that ended almost 20 years of civil war. The text formalising the legalisation of UNITA was approved by Angola's Council of Ministers almost a year ago but could not be promulgated until UNITA issued a declaration of demilitarisation. Under Angolan law, it is illegal for political parties to have troops. UNITA, under mounting international pressure to make good on peace pledges, on Friday announced its demilitarisation in a statement sent to news agencies in Lisbon. UNITA said it considered the demobilisation to be effective immediately, even if it would take up to two weeks for the remaining 1,900 men it had under arms and their generals formally to surrender their weapons. The U.N. mission in Angola says a new timetable has been agreed, leading to the completion of the peace process on April 1, and including the government declaring UNITA a legal political party. By the April 1 deadline, UNITA must relinquish all territory still under its control, shut down its radio station, the Voice of the Black Cockerel, and move its leadership to Luanda from its headquarters in Bailundo in the central highlands. During the last stage of its civil war against UNITA, which ended in 1994 with the signing of peace protocols in Zambia, the Angolan government issued over 700,000 automatic weapons to its civilian supporters.