AllianceBernstein, Barclays Global Investors, Ameriprise and Bank of America's Columbia Management were the most consistent backers of management proposals to increase executive pay, according to the study. The Corporate Library and the American Federation of State, County and Municipal Employees, one of the largest trade unions in the US, analysed mutual funds' votes in 2008 annual shareholder proposals.
Executive pay has risen sharply in the past decade, with chief executives' pay rising 24 per cent in 2007 alone to a median of $8.8m, according to the Corporate Library. In the past year, it has fallen slightly as a result of the financial crisis.
"Unfortunately, our report finds that mutual funds are increasingly supportive, as a group, of management positions on proposals dealing with executive pay, despite the current outrage over CEO pay amounts and disconnection from company performance," the study said.
In 2008, the 26 mutual fund groups included in the study voted in favour of management compensation proposals 84 per cent of the time, compared with 82 per cent in 2007 and 76 per cent in 2006.
Some mutual fund companies acted as "pay constrainers", consistently voting against pay rises. T Rowe Price, Templeton (part of Franklin Resources) and Charles Schwab were at the top of the rankings of those voting to constrain pay, the study found.
AllianceBernstein said: "We vote shares in a manner consistent with our fiduciary duty, which is in the best interests of our clients."
BGI said it voted in the best interests of its shareholders.