UK Coal is poised to sell up to 49,500 acres of brown field sites around its mines, both active and closed.
The move, which will earn the company more than £500m, will see the development of commercial, industrial and residential property on the sites. Jon Lloyd, former head of property at HBOS, joined UK Coal in July.
The company says more than 14,000 homes could be built on the land which was inherited by the firm after the coal industry was privatised in 1994.
The first planning application will be for a 60-acre site at Pontefract in Central Yorkshire in December for 900 homes and several commercial developments.