Tom Brown, chief executive of Second Curve Capital, told FT that Citi should be broken into four units: US consumer finance, international consumer finance, investment banking and wealth management.
Brown, a former banking analyst, contends that shareholder value would increase immediately if Citi were to be split into separately traded companies but what should be troubling to investors is that Prince has dismissed suggestions of a breakup.
Brown told CNBC's Melissa Lee via email that Second Curve, a fund specializing in financial stocks, he and his fund are not currently shareholders but would consider becoming one if there was chance of a breakup.
That situation appears to be unlikely at this point since an activist shareholder would probably need more than 6% of shares to gain traction, according to Jeff Harte, an analyst with Sandler O'Neill.
In the last quarter, Citi's revenue rose faster than expenses for the first time since the fourth quarter of 2005, and the bank has vowed to continue to keep costs low.