US banking regulators rejected Citigroup's so-called "living will", which is a detailed plan to wind itself down in the event of catastrophic failure, the Financial Times reported on Thursday.

In a closed-door meeting, the majority of the Federal Deposit Insurance Corporation's (FDIC) five-member board voted to reject Citi's resolution plan, according to the report.

As part of reforms passed in the wake of the financial crisis, the country's largest banks are required to have such plans to insulate taxpayers and the financial system from the impact of their failure. They are re-certified every other year by the FDIC and the Federal Reserve.

The FDIC called Citi's data controls "deficient", the FT report said.

"We continue to make substantial investments to modernise our infrastructure, including the work we're doing to automate data and regulatory reporting processes," Citi said in a statement to Reuters.

"Our balance sheet and financial health remains strong, with high levels of capital, liquidity and reserves. We continue to have confidence that Citi could be resolved without the use of taxpayer funds or an adverse impact on the financial system."

  - Reuters