Citigroup Inc.'s fourth-quarter legal expenses and costs for shrinking the business will bring the total for those items under Chief Executive Officer Michael Corbat to $13.3 billion, more than half of the bank's earnings in his 26-month tenure.

Corbat, 54, said Tuesday the New York-based bank will report $2.7 billion in quarterly legal expenses, the most since he became CEO in October 2012, data from company reports show. An estimated $800 million in costs to dismiss workers and close branches and offices will be the most since the quarter when Corbat succeeded Vikram Pandit in the CEO role.

Wall Street firms including Citigroup have faced sliding revenue from fixed-income trading, once a key profit engine, and escalating legal costs. Corbat said the bank's legal costs are tied to investigations into alleged manipulation of currency and interest-rate benchmarks as well as the bank's controls against money-laundering.