The figure is the equivalent of 5.5% of global gross domestic product (GDP) for the first three quarters of last year, the organization said, noting but it excludes income support governments provided to compensate for workplace closures during the coronavirus pandemic.
"Workplace closures continue to disrupt labour markets around the world, leading to working hour losses that are higher than previously estimated," the ILO said in its sixth report on the virus impact on the world of work.
Developing and emerging economies saw their workers, especially those in informal employment, being affected to a much greater extent than in past crises, it said.
Also, generally a decline in employment numbers was greater for women than men, the United Nations agency added.
"Just as we need to redouble our efforts to beat the virus, so we need to act urgently and at scale to overcome its economic, social and employment impacts. That includes sustaining support for jobs, businesses and incomes," ILO Director-General Guy Ryder said in a statement.
In the second quarter alone, the revised estimate of working time lost worldwide was 17.3%, which was equal to 495 million full-time jobs, compared with a previous estimate of 14% or 400 million jobs, the report said.