Citigroup is to slash 50,000 more jobs and cut costs by as much as 20% as the deepening global economic crisis continues to cripple the world's biggest banking group.

Vikram Pandit, the Citigroup chief executive, announced the fresh round of job cost cuts at a "town hall meeting" of employees.

The bank, which has 12,000 employees in the UK many of whom are based at its Canary Wharf headquarters in London, has already axed more than 23,000 jobs this year in an attempt to offset massive losses from the sub-prime mortgage crisis and the credit crunch.

Citigroup has lost more than $20bn (£13bn) in the past year as it was heavily involved in buying and selling complex mortgage-backed securities, which became worthless as the bottom fell out of the US housing market.

This latest round of cuts is much deeper than most analysts had predicted and marks Pandit's boldest move yet to arrest Citigroup's rapidly plunging …