Barclays and Credit Suisse remain Europe's leading challengers to Wall Street's powerhouse investment banks when it comes to US equities, as a secular decline in activity has fuelled more intense competition, according to a new report.

A new piece of research published on June 29 by Greenwich Associate, based on a survey of buyside institutions, put JP Morgan, Goldman Sachs and Morgan Stanley joint top in US equity trading by market share, with Bank of America Merrill Lynch, which had ranked joint top a year ago, slipping behind its three Wall Street rivals.