Pressure is building on UBS chairman Kaspar Villiger to accelerate the search for a permanent chief executive officer, Swiss weekly Sonntag reports Sunday, adding that interim CEO Sergio Ermotti signalled he wants a decision by December 15.

When former CEO Oswald Grübel abruptly stepped down late September in the wake of a rogue trading incident that cost the bank $2.3bn, UBS appointed Ermotti, the head of its European business, as interim CEO.