Fox-Pitt Kelton, the London-based investment bank, has showed that it is stepping up a gear in corporate finance by winning a mandate from the big Swiss bank Sarasin.

Fox-Pitt has over the last 10 years fed off relatively small scraps in the M&A middle market. But Sarasin is a business capitalised at around $1.2bn (€1.37bn), making it a big client for the firm.