Swissport's chief executive for western Europe, Jason Holt, said it had been "hit hard" by Covid19 with revenues "almost completely lost".
Mr Holt said: "The unfortunate fact is that there simply aren't enough aircraft flying for our business to continue running as it did before the COVID-19 outbreak, and there won't be again for some time to come.
"We must adapt to this new reality or new normal."
He pointed to industry forecasts suggesting traffic may not recover to 2019 levels until as late as 2024.
While it had survived previous tough periods such as the aftermath of the 9/11 attacks and the financial crisis, the current collapse was of a different scale to anything in living memory, Mr Holt said.
"We are now facing a long period of uncertainty and reduced flight numbers, along with significant changes taking place to the way people travel and the way goods move around the world," he added.
"There is no escaping the fact that the industry is now smaller than it was, and it will remain so for some time to come."
Annual revenues are expected to be almost 50% lower than last year, Mr Holt said.
"Hence, we must adapt by reducing the size of Swissport's workforce if we're going to survive as a company," he added.
Swissport employs around 8,500 people in the UK and Ireland, with operations across London as well as regional airports, and the jobs being lost represent 53% of the workforce.
The group employed more than 60,000 people globally prior to the crisis.
Trade unions Unite and GMB described the announcement as "devastating news".
Unite's national officer, Oliver Richardson, called on the government to intervene urgently with a financial package and an extension of the 80% furlough scheme - which is due to start tapering off at the end of July - for the aviation industry.
Thousands of jobs have already been lost across the sector as a result of the crisis, with British airways announcing 12,000 will go, Easy Jet axing up to 4,500 staff and Ryanair shedding 3,000.
On Wednesday, the Airport Operators Association (AOA), which represents more than 50 airports, said analysis of its members suggested up to 20,000 jobs were at risk and called for the government to scrap its controversial quarantine regime
Credit : skynews
