Frustrated shareholders are gearing up to unseat top directors at both Citigroup ( C) and Bank of America ( BAC) at upcoming annual meetings. The American Federation of State County and Municipal Employees, or AFSCME, is urging Citi shareholders to vote against re-electing six of the troubled companies' directors. Separately, CtW Investment Group on Thursday formally asked BofA shareholders to dump Chairman and CEO Ken Lewis. CtW also wants investors to vote against re-electing governance committee chair Thomas Ryan and lead director O. Temple Sloan at the company's annual meeting on April 29. "Mr. Lewis is responsible for an ill-advised acquisition of Merrill Lynch that transformed a bank well positioned to weather the financial crisis into one of its most costly casualties," CtW wrote in a letter to shareholders. "Subsequent missteps have further compromised his credibility with investors and regulators. "With BofA's share price down 79% in six months and financial markets still unstable, BofA 's board of directors urgently needs to recruit a CEO who can restore investor and regulatory confidence," CtW said in the letter. "Removing directors Lewis, Ryan and Sloan is the first step in this process." In a letter directed at Citi shareholders on Thursday, AFSCME, an institutional investor overseeing more than $850 million in assets through pension plans, is looking to replace directors that currently or recently have served on the company's Audit & Risk Management Committee. They include: John Deutch, Citi's audit committee chairman and a professor at Massachusetts Institute of Technology and former Defense Department Secretary, Dow Chemical ( DOW) chairman and CEO Andrew Liveris, Xerox ( XRX) Chairwoman and CEO Anne Mulcahy and Judith Rodin, the head of the Rockefeller Foundation.