Citigroup Inc has agreed to pay a $400-million fine and draw up a sweeping plan to fix persistent risk management and operational problems that have led to multiple violations and penalties over the years, U.S. regulators said on Wednesday.

The Federal Reserve and Office of the Comptroller of the Currency said the country's third-largest bank had for years failed to address the issues despite repeated warnings.

It must take "comprehensive" action to overhaul its risk management, data governance, internal controls and some compensation practices, the regulators said in separate orders and statements.

The orders, which could curtail Citi's ability to make acquisitions and personnel decisions, intensify challenges facing incoming Chief Executive Jane Fraser, who also needs to revive the bank's lagging revenues and tarnished brand.

Citi's risk management was not "commensurate with the Bank's size, complexity, and risk profile," the OCC said.

Citi responded in a statement that it was disappointed to have fallen short of regulatory expectations and had "significant remediation projects" under way. It said it had "accelerated investments and made structural changes," citing over $1 billion in spending this year to address the problems.

The OCC order gives the regulator the right to veto any significant new acquisitions by the bank, and to require changes to senior management or the bank’s board if necessary. It also requires Citi to create new senior teams devoted to addressing the issues, and for the board to provide frequent updates to regulators on how the comprehensive overhaul is progressing.

The settlement with regulators came about a month after Citi appointed Jane Fraser as chief executive, the first woman from a major Wall Street bank to hold that post. Fraser will succeed outgoing chief Michael Corbat in February.

(With input from agencies)