Shearman & Sterling London tax head Sarah Priestley has quit the firm, following the recent resignation of global private equity chief and former Weil Gotshal & Manges colleague Mark Soundy.

Priestley had been a partner at Shearman since 2013 after moving with Soundy from Weil, where she spent more than 15 years and was head of the corporate tax group. Her practice focuses on UK, multi-jurisdictional and pan-European M&A and private equity transactions.

She recently led the firm's teams advising Bridgepoint on its $100m investment in Deliveroo, and Investcorp on the £300m sale of Tyrrells Crisps to Amplify Snack Brands.

The next destination of both Soundy and Priestley is as yet unknown, although multiple sources within the market have cited Goodwin Procter as a potential new home. Shearman Paris finance partner Arnaud Fromion also left the firm last week to join Goodwin's Paris office with a team of two counsel and several associates.

The departures follow Shearman's recent partnership restructuring. Earlier this month, it internally announced plans to introduce a second non-equity tier to the partnership.

It is understood that the new tier is only applicable for associates being promoted to salaried partners and that no equity or fixed-share partners can be demoted to this rank. Instead, the firm is looking at shifting some equity partners to the fixed-share level.

Partners have grown frustrated at the firm's stalled growth. After two strong years in 2013 and 2014, average profits per equity partner fell nearly 4% in 2015, to $1.8m, while gross revenues grew by slightly less than 2% last year, to $860.5m.