Baker & McKenzie's London competition team has gifted the firm's corporate partners their first instruction from Rio Tinto.
The FTSE100 company normally uses Linklaters for its corporate work, but Bakers' corporate team got the nod because of the mining giant's longstanding relationship with its competition partners.
Competition partner Samantha Mobley, who manages the Rio Tinto relationship at Bakers, said: "Certainly as relationship partner you hope there'll be openings in other areas, but you understand that there are existing relationships with other firms in place."
She told The Lawyer she had received positive responses from Rio Tinto that it would instruct Bakers again for corporate work.
The deal saw Rio Tinto set up a joint venture with BP, advised by Herbert Smith, which will encourage cleaner energy production. The venture, Hydrogen Energy, will work with governments to develop hydrogen-fuelled projects. Bakers global head of M&A Tim Gee led on the deal along with senior associate Richard Kelly. As part of the agreement, Rio Tinto will pay BP $33m (£16.7m).
Bakers' appearance on what has been a territory monopolised by Linklaters comes at a time of change for Rio Tinto. The company shook up its internal legal function at the beginning of 2007, introducing the role of global general counsel and centralising its legal function to give a tighter rein on external legal spend.