Zuckerberg's role at Facebook challenged by leading investor

Mark Zuckerberg's tight control over Facebook is under assault from shareholders even before his social networking giant joins the public market.

One of the largest pension funds in the US has promised to take on the company over weak corporate governance structures and the highly unusual decision-making power handed to its 27-year-old founder.

The California State Teachers' Retirement System, Calstrs, says it will raise its concerns in a letter to Facebook and try to get it to change its policies before a stock-market flotation planned for this spring.

Facebook said last week that it would sell around $5bn (£3bn) shares to the public, an offering that could value the company at $75bn-$100bn.

In a prospectus for the share offering, Mr Zuckerberg's dominance over Facebook's decision making became clear for the first time. He owns about 28 per cent of Facebook and some of his early backers, including DST Global and Accel Partners, have given him irrevocable voting rights over their stakes, too. In addition, the shares being sold to the public will have only one-tenth of the voting power of founders' shares.

Mr Zuckerberg has the sole right to appoint his successor, and if founders' shares dwindle over time as a proportion of the company, further restrictions will kick in limiting the power of other shareholders to nominate board members.

Calstrs, which manages $145bn, said "there should be some more respect for capital".