The days when Wall Street banks could blithely hand out half their revenue in compensation to their staff without a murmur from shareholders have come to an end. In an era of leaner times and tighter regulation, big mutual funds and pensions are growing more vocal in pushing executives at investment banks to rein in pay and bonuses and consider more staff cuts. Investors worry that bank employees are getting too big a piece of a shrinking pie, leaving shareholders a much smaller slice.

So far, much of the jousting is taking place behind closed doors. But the debate over whether investment banks should keep devoting roughly 50% of revenue to employee compensation is starting to enter the public realm through proxy battles and as more large shareholders speak out on the issue.