A former senior executive at Citigroup Inc. has decided to take legal action against the company to force it to resume paying his multi-million dollar severance package that has been frozen for six months, the Financial Times said, citing people close to the situation.

Kevin Kessinger, who was formerly in charge of operations and technology at Citigroup, is taking the company to arbitration, an out-of-court dispute resolution mechanism, according to the paper.

Kessinger is now the chief information officer at Canada's Toronto Dominion Bank, the paper said.

A Citigroup spokesman in Hong Kong was not immediately available for comment, while Kessinger could not be immediately reached for comment by Reuters outside regular Canadian business hours.

In June, the Wall Street Journal had reported that Citi told about five former top executives they would not be paid tens of millions of dollars in promised severance payouts.