John Costas, the former head of UBS’ ill-fated hedge fund arm Dillon Read Capital Management who left after losses forced the unit's closure in 2007, is having a fresh crack at investment banking after re-emerging at the helm of The Princeridge Group, a boutique that counts several of his ex-UBS colleagues among its more than 40 staff.

Costas, who ran UBS' investment bank before switching to be chief executive of Dillon Read, left the Swiss group after trading losses sparked the winding down of the hedge fund unit that had been his brainchild, in early 2007.