Every industry association faces a struggle in coaxing rival companies to work together towards a shared goal. But the task of the Wholesale Market Brokers’ Association is particularly daunting. This trade body, which traces its roots to the 1960s, represents the interests of interdealer-brokers, a coterie of often combative firms that execute trades between banks.

The fierce rivalry between these firms, masters of the $592 trillion (€411 trillion) over-the-counter markets, is legendary and has resulted in several high-profile staff-recruiting battles and court cases. Nevertheless, regulatory concerns over the role of OTC markets in deepening the financial crisis has pushed them together, according to David Clark, a 38-year City veteran who has chaired the WMBA since 2006.