Deutsche Bank has made the first of the 18,000 job cuts announced on Sunday as part of a radical reorganisation.
Teams of share traders in Tokyo and other offices in Asia were told on Monday that their jobs were going.
In London, some staff stayed away from work after being told their passes would stop working at 11:00.
A spokesperson said the aim of the changes, which will shrink its investment banking business, was to make the bank "leaner and stronger".
Deutsche Bank is yet to specify exactly where the rest of the jobs will be lost.
But it will pull out of activities related to trading shares, much of which takes place in London and New York.
With almost 8,000 staff, Deutsche Bank is one of the biggest employers in the City of London.
"We will retain a significant presence here and remain a close partner to our UK clients and to international institutions that want to access the London market," it said in a statement on Monday.
Outside the bank's London HQ staff have been seen speaking on their phones - with some visibly upset - just hours after arriving at work.
Some workers have been sent home while others are still waiting to find out whether their jobs are at risk.
