Oonagh Whitty, who has been with Watson Farley for 15 years, will work closely with the corporate finance team at Lathams' London office and is the third high profile lawyer to join the firm in the last month.
As exclusively revealed in The Lawyer (7 August), Kevin Dunn, European general counsel at GE Capital, is due to join the firm, while just over a week ago Weil Gotshal & Manges' head of banking James Chesterman announced he was joining Latham's acquisition finance practice (The Lawyer, 14 August).
Lathams is the latest US firm in London to invest in a UK tax lawyer to support its corporate finance team.
Last month, Milbank Tweed Hadley & McCloy recruited corporate tax partner Russell Jacobs from Cadwalader Wickersham & Taft.
US firms in London have been concentrating on building up their corporate finance practices in order to compete with the UK magic circle firms for lucrative instructions from City investment banks.
Tax work has normally been supplied by accountants, the bar or by referring work to other UK firms such as Travers Smith Braithwaite.
Joe Blum, managing partner at Lathams' London office, says: "You will find that in M&A work in particular and some investment fund work there is a strong need for tax.
"Some US firms have been strengthening this, whereas before they would go to accountants or the bar."
Phillip Fletcher, managing partner at Milbank Tweed's London office, says: "We don't think that you can do complex trans-border and structured finance work without a sophisticated tax capability, which is why we brought Russell Jacobs on board."
One source says that it is a major coup to persuade a UK tax partner to move to a US firm. "Tax partners are generally less risk-taking and generally do not have their own practices.
"They need to have critical mass - tax practitioners need other tax practitioners."
Blum says that the firm will not be recruiting any more tax partners but will take on an associate to support Whitty.