An association of New South Wales colliery proprietors was formed in October 1905 but it was not until June 1942 that it was registered as an industrial union under the Commonwealth Conciliation and Arbitration Act as the New South Wales Combined Colliery Proprietors' Association. Its members were four separate and autonomous organisations: the Northern Colliery Proprietors' Association which dated from 1866 and operated in Sydney and Newcastle, Northern Collieries Limited representing other northern colliery proprietors, the Southern Colliery Proprietors' Association which dated from 1889 in the Burragorang Valley and the Southern Tablelands, and the Western Coal Association which was operating by 1929 in Lithgow and other western areas. The Northern, Southern and Western associations merged in 1964 under the umbrella body. The New South Wales Combined Colliery Proprietors' Association was deregistered in 1976 but continued to operate as an industry association. It was incorporated in New South Wales as the New South Wales Colliery Proprietors' Association Limited in June 1982, but was commonly known as the New South Wales Coal Association. It merged with the New South Wales Chamber of Mines in 1995 to form the NSW Minerals Council.