Government prosecutors said Monday they will oppose a bid to reopen the trial of the ``Sharpeville Six,'' a group of blacks convicted of complicity in a mob killing and sentenced to death. P.J. Van Zyl, registrar of the Pretoria Supreme Court, said the attorney general of Transvaal province had filed a notice of intention to oppose the defense lawyers' application to reopen the trial. He said a ruling was expected May 3. The defendants, five men and a woman, were granted a stay of execution on March 17, the day before they were scheduled to be hanged. The stay was ordered after their lawyers filed papers claiming a key state witness had been coerced by police into giving false testimony. Defense lawyers asked that the trial be reopened to consider that claim and to review the credibility of other state witnesses. Many human rights organizations and Western leaders have appealed to South Africa's white-controlled government to commute the death sentences. The six were convicted of complicity in the September 1984 killing of a black municipal councilor, Kuzwayo Dhlamini, during riots against rent increases in the black township of Sharpeville, south of Johannesburg. But they were not found guilty of physically contributing to Dhlamini's death. They were convicted under the doctrine of common purpose, which holds defendants responsible if they are found to be participants in mob violence. The government has said their conduct inluded throwing stones at Dhlamini, helping set his house afire and slapping a woman who begged the crowd not to burn him. Black government employees frequently are targets of militants battling to overthrow the government and its policy of apartheid. By law and custom, apartheid establishes a racially segregated society in which the 26 million blacks have no vote in national affairs. The 5 million whites control the economy and maintain separate districts, schools and health services.