The world's largest investment banks have already begun cutting dealmaker jobs as revenues tumble after last year's hiring spree.

Figures from data provider Coalition Greenwich suggest that the 12 largest investment banks in its analysis — Bank of America, Barclays, BNP Paribas, Citigroup, Credit Suisse, Deutsche Bank, Goldman Sachs, HSBC, JPMorgan, Morgan Stanley, SocGen and UBS — have trimmed their ranks of investment bankers in the second quarter as brutal market conditions bed in.