The fire at apetito in Trowbridge broke out in its pastry factory in Canal Road, which is separate from the main factory.
A spokesman for Paul Freeston, apetito's UK chief executive officer, said all 60 members of staff who work in the pastry factory have been evacuated and there are no reports of any injuries.
Mr Freeston was at the scene this afternoon.
The company said the main factory, which is central to its care home catering operation, is completely unaffected.
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