Paul Hastings Former Chair-Elect O’Sullivan Leaves Law Firm (1)

Ronan O’Sullivan, the London lawyer once picked as the next chairman at Paul Hastings, has left the law firm.

O’Sullivan’s departure comes as New York lawyer Frank Lopez is set next month to take over the firm’s top role from longtime Paul Hastings leader Seth Zachary. O’Sullivan was initially tapped for the job, but later decided against it for “personal reasons,” according to the firm.

Corporate filings in the UK show that O’Sullivan was removed as a member of the firm on Aug. 16. A Paul Hastings spokesman confirmed O’Sullivan’s departure.

O’Sullivan is a 16-year Paul Hastings veteran and former head of its London office, whose clients include soccer team owner City Football Group. He spearheaded a UK growth plan that saw the firm’s London office double in size to more than 100 lawyers.

He was largely considered the heir apparent to Zachary after being named global managing partner in 2018. O’Sullivan was elected three years later to be next line for the chairman position. Teri O’Brien, the former co-chair of Paul Hastings global securities and capital markets practice, was slated to be O’Sullivan’s second-in-command.

O’Brien earlier this year left the firm for Latham & Watkins.

Lopez, who takes the reins Oct. 15, was elected in a vote held shortly after the firm announced O’Sullivan’s change of heart. Although he had been with the firm less than three years, the former Proskauer Rose partner earned Zachary’s backing and was elected—along with incoming No. 2 Sherrese Smith—on a first-ballot, super majority vote.

The firm, which advises some of Wall Street’s top players, has in recent years bolstered an already strong capital markets team while also continuing to focus on lucrative mergers and acquisitions and private equity work. It poached a 43-lawyer bankruptcy from New York’s Stroock & Stroock & Lavan in March.

Other notable departures from Paul Hastings include white collar partners Kenneth Breen and Phara Guberman, who left for Cadwalader, Wickersham & Taft earlier this month.