Europe’s top banks have seen a sharp reduction in their share of the region’s M&A as Americans and independent boutiques take a bigger slice of the pie.

The big four local players - Barclays, Credit Suisse, Deutsche Bank and UBS - worked on 37.5% of the total value of European transactions in the year to May 8, according to Dealogic. It is the lowest combined market share for the four since at least 2010. In 2012 it was as high as 77%.