LABOR UNIONS "Dual shop" legislation is opposed by contractors. 1:11,W Je 9, 1986 p.1,16 Oil and mine unions call off merger plan. RMN F 25, 1988 p.63,68 Two largest unions: Oil Chemical and Atanic Workers, and United Mine Workers, discuss merger. FM F 24, 1988 p.61 Bill to liberalize union elections okM. FM Mr 18, 1988 p.16