ABOUT 50 firefighters were called in to battle a major factory fire in Clayton South.
A Metropolitan Fire Brigade spokeswoman said emergency services were called to the Melbourne Machinery Co. in Main Street, about 7pm on Saturday night.
Flames were tearing through the factory's roof when firefighters arrived.
Aerial firefighting units were needed to help contain the fire, which took about 45 minutes to bring under control.
The factory sustained extensive damage in the blaze and a large portion of the building's roof collapsed.
No injuries were reported and firefighters managed to stop the fire from spreading to adjoining buildings.
“Many racks of industrial parts at the rear of the premises were also protected,” the MFB spokeswoman said.
The factory contained industrial machinery, parts and associated equipment.
Nearby residents were warned to shut windows and doors due to thick smoke, while local roads were closed to traffic.
Fire investigators were working on Sunday morning to determine the cause of the blaze.