Credit Suisse chief executive Tidjane Thiam today said his three-year turnaround plan was having a "positive impact" on performance at the Swiss bank, despite big tax charges leaving it in the red for 2017 — a third straight annual loss.

Thiam made the claim as Credit Suisse confirmed it had taken a hefty hit from US tax changes and a rates trading settlement with market authorities, which dragged it to a Sfr2.1bn ($2.2bn) fourth-quarter loss.