Investors controlling a big block of shares in JP Morgan have called for the role of CEO and chairman of the board of director roles, currently held by Jamie Dimon - to be split.

Investors controlling more than 16 million shares in JP Morgan have called for the chief executive and chair of the board of directors roles - currently both held by Jamie Dimon - to be split.

The coalition of investors calling for the move includes the AFSCME Employees Pension Plan, the Connecticut Retirement Plans and Trust Funds, Hermes Equity Ownership Services and the NYC Pension Funds.

The parties are jointly filing a proposal citing “investor concerns with the board’s oversight in the wake of the London Whale losses” and other recent regulatory sanctions.

JP Morgan shareholders will vote on the proposal at the company’s 2013 annual meeting in May, the investors’ statement said.

Dimon, who took up the CEO role at the end of 2005, was appointed chairman a year later, on 31 December 2006. This is not the first time a shareholder proposal has called for a split of the roles since then, after a similar proposal received a 40 per cent favourable vote at the 2012 annual meeting.

The proposal is a non-binding resolution, meaning that even if a 50 per cent favorable vote were achieved, the decision would lie with the board ultimately.

However, it would call the issue to the board’s attention as an investor concern, pointed out Matthew Sweeney, a spokesperson for the NYC Pension Funds. He added that the organisation votes in favour of splitting the roles as a matter of policy when such resolutions come up within its portfolio of holdings.

JP Morgan declined to comment.

The shareholder group cited a June 2012 report by GMI Ratings, which found that five-year shareowner returns were nearly 28 per cent higher at companies with a separate CEO and board chair.

“More and more companies have independent board chairs. Institutional Shareholder Services, a leading independent proxy advisor, reported that 21.5 per cent of S&P 500 firms had an independent chair in 2012, up from 18.1 per cent in 2010,” the statement said.

The shareholders also cited a 2007 Booz & Co study, which found that in 2006, all of the underperforming North American companies with long-tenured CEOs lacked an independent board chair.