Herbert Smith Freehills' (HSF) Asia managing partner Mark Johnson is to join Debevoise & Plimpton in Hong Kong after 20 years with the UK firm.

Johnson, who is among the city's top litigators, will be the first disputes partner based permanently in Debevoise's Hong Kong office, and will give the US firm a fully-fledged local litigation offering.

His hire comes just weeks after the firm obtained its licence to practice local law in Hong Kong, and less than two years since Davis Polk & Wardwell launched its own local disputes practice with the hire of Martin Rogers and his team from UK rival Clifford Chance.

"Mark has a long and successful track record in the Asia market and has built an impressive reputation as a leading white collar and regulatory lawyer," said the head of Debevoise' Asia and European disputes practice and former UK attorney general Lord Peter Goldsmith.

"His addition to the team will benefit our clients not only in Asia, but also around the world. It adds further weight to our global white collar and regulatory defense practice, and ensures we continue to have market-leading teams in the world's major financial hubs."

Johnson has been in the region for 25 years, advising on shareholder and director disputes, internal and regulatory investigations, commercial litigation, and matters concerning regulators the Hong Kong Securities & Futures Commission (SFC), the Hong Kong Monetary Authority (HKMA) and the Hong Kong Stock Exchange.

He oversaw the opening of Herbert Smith's disputes practices in Singapore, Jakarta, Bangkok, Beijing, Seoul, Shanghai and Tokyo, and has been Asia managing partner at the firm since 2011, when he took over from corporate rainmaker Ashley Alder, who left for the SFC.

HSF's global head of disputes, Justin D'Agostino denied that his departure would have a significant impact on the practice.

He said in a statement: "Quite simply we have the dominant disputes platform in Hong Kong and across Asia and we do the best work for the best clients in the region.

"We continue to attract top names across our market leading global disputes practice including, most recently, John Siu and Will Hallatt in Hong Kong, regulatory heavyweight Andrew Procter in London and former Assistant US Attorney John O'Donnell in New York, and our energies remain focussed on building our team of highly talented lawyers."