Mr Dimon, chairman and chief executive of JPMorgan Chase, has led a months-long series of discussions to draw up a blueprint for how boards should conduct themselves and engage with shareholders. The effort, revealed by the Financial Times in February, involves the leaders of the largest asset management companies and investors such as Warren Buffett. More recently it has expanded to include several big US companies, including General Electric, General Motors and Verizon. Its aim has been to take some of the heat out of corporate governance controversies by getting the largest US shareholder groups to agree common standards and to promote long-term planning by companies. However, Abigail Johnson, Fidelity’s chief executive, decided not to sign up to a draft statement of principles that had been circulated among the group, which runs to about a dozen pages, according to people involved. Fidelity confirmed that it would sit on the sidelines, although it said the group had done “valuable” work. “We take corporate governance very seriously at Fidelity and have long had detailed proxy voting guidelines which we regularly update,” the investment group said. “Every company has its own distinct business model, culture and values, and thus, we generally do not sign on to blanket industry documents.