Freshfields Bruckhaus Deringer City corporate partner Philip Richards has been permanently appointed to lead Rio Tinto's legal team after filling in in the role on a two-month secondment.

He has been handed the role of group executive for legal after he was seconded to Rio Tinto in December, following the departure of previous head Debra Valentine.

At Rio, Richards will have responsibility for all group legal services and will also join the company's executive committee.

Rio Tinto chief executive Jean-Sebastien Jacques said: "Philip has demonstrated in his time with us that his significant almost 40-year experience in legal affairs will be a real asset for our company. He has quickly embraced the strong Rio Tinto culture and I am very pleased to have him join our team."

Before his arrival, chief financial officer Chris Lynch had taken on temporary control of corporate legal and regulatory affairs since Valentine's departure in November.

Valentine had been due to retire in May. However, Rio Tinto terminated her contract last year while undertaking an inquiry into payments amounting to $10.5m (£8.5m) made to a consultant in 2011. The mining giant concluded that she "failed to maintain the standards expected" of her under the company's code of conduct. At the same time, Rio Tinto also axed the role of energy and minerals chief executive, Alan Davies, citing the same reasons.

At Freshfields, Richards established the magic circle firm's financial institutions group and co-headed its Italian offices when he was based in Milan.

He has worked with a range of major clients, including Barclays, Tesco, Prudential, Liberty Global and Swiss Re. In January, Richards was part of Freshfields' team acting for the London Stock Exchange on the €510m (£432m) sale of its French arm to rival Euronext.

Typically, Rio Tinto does not turn to Freshfields for legal advice. Its longstanding advisers include Sullivan & Cromwell, Linklaters and the magic circle firm's Australia ally, Allens.