LONDON (Reuters) - Rupert Murdoch's campaign to keep control of News Corporation suffered a fresh blow on Friday after another key shareholder group called for his eviction from the board of the embattled media company.

Hermes Equity Ownership Services (HEOS) the shareholder advisory service affiliated to Britain's largest pension fund, issued a rallying cry to investors to eject Murdoch and sons James and Lachlan from the board at its upcoming annual meeting on October 21.

The organization, which votes on behalf of the BT Pension Fund and more than 20 other institutional clients running $140 billion of assets, has also called for an independent investigation into the phone hacking scandal that forced the closure of top-selling British tabloid The News of the World.

"The time is right for the company to appoint an independent chairman to rebuild trust, help correct the governance discount, and ensure that the interests of all investors are properly represented," Jennifer Walmsley, Director of Hermes Equity Ownership Services, said.

"News Corp has not reacted with sufficient urgency to investor concerns about its board composition and corporate culture," Walmsley added.

HEOS also said it would withhold support for the re-election of directors Arthur Siskind and Andrew Knight, citing concerns for their independence.

The statement from HEOS follows a flurry of anti-Murdoch lobbying from corporate governance watchdogs all over the world.

Earlier this week, News Corp hit back at critics including ISS in a letter to shareholders which said the "disproportionate focus" on the News of the World phone hacking saga was "misguided."

(Reporting by Sinead Cruise; Editing by Chris Vellacott and Hans-Juergen Peters)

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