JPMorgan CEO Jamie Dimon's revelation about his illness has sparked questions about the bank's succession plan and will likely rekindle the debate about separating the roles of chief executive and chairman, both of which Dimon has held since 2006.

Dimon revealed earlier that he has been diagnosed with throat cancer, but noted that he "will be able to continue to be actively involved in our business, and we will continue to run the company as normal".

Even though Dimon said the prognosis for his throat cancer is "excellent" and the illness is "curable", his absence from the company for eight weeks to undergo treatment is raising questions over who is ready to fill in the post, the Wall Street Journal reported.

Over the next several weeks the board should be clear whether the treatment will lead to business as usual or a leave of absence resulting in a change in assignment, Deborah Cornwall, managing director at leadership and governance consultancy Corlund Group told the newspaper.

A person familiar the bank's plan told WSJ that JPMorgan retail head Gordon Smith and asset-management chief Mary Callahan Erdoes are two of the top candidates to take on bigger roles if there is a requirement for an immediate change in leadership.

Longer-term succession candidates include chief operating officer Matt Zames, commercial banking chief Doug Petno, corporate and investment banking chief Daniel Pinto, chief financial officer Marianne Lake and chief risk officer Ashley Bacon.

Earlier, there were calls to separate the roles of CEO and chairman after JPMorgan posted a $6bn trading loss in 2012. The proposal was defeated at that time, but with Dimon's current health situation its likely to resurface.

Janet Tavakoli, president of Tavakoli Structured Finance, said: "Given the financial crisis and best practices for corporate governance, it's remarkable that a bank of the size and systemic importance of JPMorgan finds itself in a position of having one man as both chairman and CEO. Jamie Dimon's recent news highlights the risk in that folly."

Dimon recently announced that he plans to remain chairman and chief executive of JPM for another five years.