Nabarro Nathanson's Niall Logan helped create industrial history in what is believed to be British Coal's biggest single legal transaction.
The property partner took part in a marathon five-hour signing and sealing of hundreds of documents transferring mining rights to the private sector.
Each document had to be stamped up to 10 times with the official British Coal seal before being handed over. It has never seen so much action, says seal keeper Martin Povey.
Logan says the project was the culmination of work which began two years ago.
"I believe this must have been one of the biggest single legal transactions involving British Coal," he says.
Herbert Smith acted for British Coal alongside Nabarros while Clifford Chance acted for the Government.
Mining rights have now been transferred to the successful bidders including RJB Mining which will be operating the three main regions in England.
Melvin Garness, company secretary, says RJB is currently reviewing its legal services.
It is understood that Nabarros, and McLure Naismith Anderson & Gardiner in Scotland, will continue to advise British Coal on its non-operational assets. The firms are also acting for the new Coal Authority.