Squire Patton Boggs has hired former Ashurst managing partner James Collis, as the U.S. firm looks to rebuild its London operation following several departures.

Collis was a finance partner in legacy firm Ashurst's Paris office from 2005 to 2012.

He was then appointed managing partner of the U.K. firm and became a member of the firm's board. Following the firm's merger with legacy Australian firm Blake Dawson, he took on the role of inaugural managing partner of the combined firm in 2013.

After stepping down from the position in 2016, he returned to fee-earning in the firm's banking practice in London.

Squires' European managing partner Jane Haxby said in a statement: "James is one of the City's leading legal professionals, an outstanding practitioner in finance law and a skilled and highly respected managing partner, who has successfully overseen one of the largest law firm mergers and who has implemented numerous new development programmes and strategic initiatives."

The recruitment of Collis follows several partner departures from Squires' London office to U.S. rival Crowell & Moring.

Squire's U.K. litigation head Laurence Winston, London insolvency head Cathryn Williams, insolvency partner Paul Muscutt and infrastructure partner Robin Baillie all left the firm to join Crowell's London outpost earlier this year.

The team move reunited them with Squire's former London managing partner Robert Weekes, who joined Crowell at the end of 2018.

A spokesperson for Ashurst said in a statement: "We thank James for his contribution to the firm and wish him well for the future."