Research by Emolument for the Financial Times found that pay dropped by 2% last year to $99,000 (£79,400). Salaries in the industry have fallen by nearly 20% since 2014.
Asset management companies are seeing profit margins squeezed as growing numbers of investors flock to "passive" funds - portfolios which mirror a market index, rather than try to outperform it as active fund managers do.
That shift is being driven by record low interest rates and depressed global growth in the wake of the financial crisis, which has made market out-performance increasingly difficult. The FT reported last year that 99% of actively-managed US funds had failed to beat their benchmark since 2006.
Fund managers are also facing competition from so-called "robo advisors" - online wealth managers that use technology and automation to offer much lower fees than those offered by traditional money managers.
As a result, active funds have faced increasing scrutiny of fees and extensive research suggests that almost all of them underperform against benchmarks.
Scottish fund house Aberdeen Asset Management announced last week that it had frozen the salaries of those earning over £75,000 due to the group's "financial performance in 2016."
Passive funds now account for around one-third of all mutual fund assets - up from one-quarter just three years ago.