In trying to find the perfect recipe for an initial public offering, issuers have been turning to more and more chefs. Now it seems they are getting in each other’s way.

In the year to date, 45% of European IPOs have had just one bookrunner on the deal, according to Thomson Reuters, down from 51% last year and 88% a decade ago. Meanwhile, almost15% of deals have had four or more banks involved, taking the average number of bookrunners to 2.27, which is a record high.