Broker Marsh arranged the cover for the plastics factory, which exploded in Glasgow this week, sources said.
Allianz Cornhill confirmed they had underwritten both the property and employers' liability.
GAB Robins has been assigned to investigate the loss, said an industry insider. According to a report, local councillor Hanzala Malik said the factory had passed safety tests only a few months ago. It said the Health and Safety Executive was planning to launch an investigation into the explosion.
Sixteen people were left trapped in rubble after the explosion. The four-story building was levelled in the blast. Eyewitnesses claimed that the explosion of an industrial gas oven was the cause of the accident.
The explosion at Stockline Plastics on Grovepark
Street, Glasgow occurred at around midday, said Strathclyde Police.