Landwell is taking on Stephen Mostyn-Williams, the former head of acquisition finance at Shearman & Sterling's London office.
Mostyn-Williams will join as business development director and will work at least three days a week at the firm, which is linked to PricewaterhouseCoopers (PwC).
He will continue with his new job as managing director at debt fund AIG Mezzvest (The Lawyer, 8 January).
At Landwell his role will be to develop the London business through a combination of recruitment, profile raising, winning work and practice development.
Landwell's London senior partner Chris Arnheim says: "I think this is exactly what Landwell needs at the moment. During the past year we have quietly moved the practice forward quite considerably, but Landwell is still a little bit invisible.
"What we need is to recruit some very high-profile senior lawyers who can catch people's attention. To take Landwell to the next stage we have to raise our profile with clients and with potential recruits."
Landwell, then Arnheim Tite & Lewis, was rocked last year by the departure of name partners Christopher Tite and Mark Lewis to launch Ernst & Young's law firm Tite & Lewis.
But in October it recruited Norton Rose banking lawyer Celia Gardiner as a partner, and has been expanding its private equity and corporate finance capability since then. The corporate team accounts for about half of the firm's turnover, and recent deals include advising the management on the £670m buyout of Center Parcs led by DB Capital Partners.
Mostyn-Williams has relationships with investment and commercial banks, and with financial sponsors. He says: "I wanted to stop doing the chargeable hours treadmill, and the skills that I have and the contacts I have developed are where I can add value."
Before joining Shearman & Sterling in September 1998 he was head of banking and international finance at Ashurst Morris Crisp.