A Citigroup Inc. trader works on the floor of the New York Stock Exchange

Citigroup's investment banking business could shed as much as half of its 20,000 technology and operations staff in the next five years due to automation, the Financial Times reported on Monday.

Operational positions were the "most fertile for machine processing," the FT reported, citing Jamie Forese, chief executive officer of the bank's institutional clients group.

"We've got 20,000 operational roles. Over the next five years could you make it 10,000?" Forese was quoted as saying in the FT article.

Under tremendous pressure from investors to boost profits, but unable to grow revenue much, banks have increasingly turned to technology to reduce costs.