New Zealand's state-owned coal miner Solid Energy announced agreements to sell its working coal mines, which could return between 45 per cent to 55 per cent of the NZ$395 million owed to a range of banks by the company, which was put into administration by those banks in August last year.Solid Energy chief executive officer Andy Coupe said the return to creditors was better than the 15 per cent to 20 per cent initially indicated and the 35 per cent to 40 per cent they had been expecting earlier this year. Solid Energy agreed to sell its Stockton, Rotowaro and Maramarua mines to Phoenix Coal, a joint venture between Bathurst Resources and Talley's Group. The New Vale and Ohai mines were sold to Palmer MH Group, while the Strongman and Liverpool mines were sold to Birchfield Coal Mines. The terms of each sale were not detailed, but Coupe told Banking Day the total proceeds would be in a range of 45 to 55 per cent of the amount owed to banks.Solid Energy's creditors include ANZ, Commonwealth Bank of Australia, National Australia Bank's BNZ, Westpac and the Bank of Tokyo-Mitsubishi. The New Zealand mutually-owned regional bank TSB wrote off all of its NZ$53.9 million loan to Solid Energy last year, so is expected to benefit from significant write-backs.