Herbert Smith could add up to $15m (£9.3m) in annual fee income as a result of the hire of the six-partner Chadbourne & Parke team for its New York launch, with the group also handing the firm a new client relationship with tobacco giant RJ Reynolds.

The team, which includes five partners in New York and one partner in London, joined Herbert Smith last week from the US firm, where they have collectively billed an average of $15m a year in recent times.

The billings can be attributed to a range of high-profile clients, with RJ Reynolds – which makes the Camel brand of cigarettes – expected to move with the group to become a client at Herbert Smith alongside the much-touted British American Tobacco, which the UK firm already has strong ties with.

The group is led by former Chadbourne litigation head Thomas Riley, who has been appointed as New York managing partner.

Former product liability and defence practice group head Gregory Loss, David Wallace, Allison Alcasabas and Joseph Falcone are also based in the US state.

The sixth partner, Philip Pfeffer, has moved from the US firm's London arm to Herbert Smith's City office.

The group has worked on some of the biggest tobacco litigation cases over the past decade, including the US Department of Justice's $280bn (£174bn) claim against major cigarette manufacturers, which began in 1999.

A Herbert Smith spokesperson said: "We do not comment on confidential client matters".

The news comes after it emerged last week that an additional 15 fee earners have also moved over from Chadbourne, 13 of whom are based in the US.

Herbert Smith is still looking to recruit further fee earners for the new office's anti-corruption and cross-border investigations team, with a view to completing this by the end of the year.