A 15% increase in revenues for City banks advising on mergers and acquisitions work has pulled in more than $5bn of fees so far in 2018, but the flurry of mega-deals could soon come to an end.

M&A fees have helped offset a decline in equity advisory work so far this year, but bankers caution that the surge in deals of over $10bn that emerged in the first half of 2018 in Europe, the Middle East and Africa, could be replaced by smaller and mid-sized deals for the rest of this year and into 2019.