Profits at Robey Warshaw rose 127% last year, a period in which the Mayfair advisory firm secured a landmark mandate from its first US client.

According to accounts filed at the UK’s Companies House this week, Robey Warshaw’s operating profits for the year to March 31 were £48.4m, up from £21.3m in the previous 12-month period. Revenues doubled to almost £59m.