BioNTech has announced it will close three German sites in Idar-Oberstein, Marburg and Tübingen that failed to sell.
The German COVID-19 vaccine manufacturer cited a difficult market and investment environment as the reason it failed to find a buyer for the sites.
"Despite the best efforts of all those involved and a wide-ranging sales process, it has unfortunately not been possible to finalise a sale," said a spokesperson.
The company will also end operations at its Singapore plant, bought from Novartis in 2022.
The move is expected to affect up to 1860 jobs.
The spokesperson added that the biotech firm had agreed with the works council on socially responsible solutions and supplementary redundancy terms for affected staff.
An unsuccessful search for buyers
BioNTech had announced back in May that it would seek buyers for the Idar-Oberstein, Marburg and Tübingen sites, as well as in Singapore, or otherwise wind them down.