Group says News Corp has not addressed board structure and corporate culture and call on Murdoch to step down as chairman

Shareholders have stepped up their campaign to remove Rupert Murdoch as chairman of News Corporation ahead of the media company's annual meeting this month.

Hermes, a British fund manager that controls £24.8bn assets, joined an action on Wednesday launched by dissident shareholders seeking to oust News Corp's chairman in the wake of the phone-hacking scandal.

Glass Lewis, one of the largest shareholder advisory groups, has also recommended its clients vote for the appointment of an independent chair. This is the second year that major shareholders have rounded on Murdoch and his board.

Hans Hirt, global head of corporate engagement at Hermes, said: "While we acknowledge the recent board changes made by the company, News Corp has still not sufficiently addressed the significant shareholder concerns about its board structure and corporate culture highlighted at last year's annual meeting. The time is right for the company to appoint an independent chair in order to rebuild trust, and ensure that the interests of all investors are more properly represented."

The resolution was co-filed by Christian Brothers Investment Services (CBIS) and members of the Local Authority Pension Fund Forum (LAPFF). It will be voted on at the company's annual meeting in Los Angeles on 16 October.

A similar vote last year failed to pass. Murdoch and his family own about 12% of the media giant but control 40% of the vote because of News Corp's dual class share structure. Last year, the majority of independent voters voted against much of News Corp's board including Murdoch's sons Lachlan and James.

This year's meeting comes amid rumours that News Corp is considering appointing James Murdoch to head Fox Networks, the division that runs the firm's flagship Fox channel. Such a move would come in a year that has seen James Murdoch criticised for his handling of the hacking revelations and resign as chairman of both News International, the company's British newspaper division, and BSkyB, the British satellite broadcaster that it controls.

Julie Tanner, director of socially responsible investing at CBIS, called the speculation a "slap in the face for shareholders, not to mention victims of the hacking scandal".