In April 1931, the East Greta Coal Mining Co. was taken over by J & A Brown and Abermain Seaham Collieries Ltd, which gave them a 50% share of SMR. In the 1940s, due to changes in company laws, South Maitland Railways Ltd was changed to South Maitland Railways Proprietary Limited. With the merger of JABAS with Caledonian Collieries Ltd in 1960 and the formation of Coal & Allied Industries Ltd (C&A), the 50% share in SMR held by JABAS passed to this new company. In 1967, Coal & Allied purchased Hebburn Ltd which then gave them 100% control of South Maitland Railways. The SMR continued as a subsidiary of Coal & Allied until 1989 when SMR Pty Ltd was bought by a private consortium.