State-owned power companies whose coal blocks were taken back last week have questioned the government's move to revoke their licences while sparing private companies. Public sector firms, including NTPC, Damodar Valley Corporation, Andhra Pradesh Power Generation Corp and Jharkhand State Electricity Board, said they have invested huge sums in developing the mines while many private firms have not even begun preliminary groundwork. A senior coal ministry official, however, said the decision to cancel allocations was made after a thorough evaluation. On Wednesday, the coal ministry decided to revoke licences of 14 coal blocks, 12 of which belonged to state-run companies. The blocks were de-allocated because the mines were not developed on time. But the ministry action came as a surprise because this was the first time when so many blocks were de-allocated in one go. The ministry had so far cancelled only 10 blocks but that was over several years. The blocks will now go to state-run Coal India. A report of a review committee headed by coal ministry additional secretary Alok Perti had recommended issuing cancellation orders to 26 firms, including private players like Tata Steel, Hindalco Industries, JSW Steel and Jindal Power. However, coal blocks of only two private companies Shree Baidyanath Ayurved and Bhatia International have been revoked. NTPC has invested over Rs 300 crore in the five mines which were cancelled, chairman and managing director Arup Roy Choudhury said, adding that his company had a better record in mines development in comparison to CIL.