Tite and Lewis - the firm's former joint senior partner - have both jumped ship to set up an associated law firm for Big Five accountancy rival, Ernst & Young.
The news comes less than a year after AT&L suffered the loss of six salaried partners to another Big Five rival. All left to set up KPMG's associated law firm, KLegal.
It is understood that the Tite & Lewis left following disagreements over the way the UK practice is to be developed.
AT&L confirmed these latest resignations in a terse, one line statement. Chris Arnheim has assumed leadership of the UK firm with immediate effect.
He will be aided by Simmons & Simmons' former managing director, Alan Morris, who recently joined PWC to head up the global operations of its legal network, Landwell