More than 25 firefighters are battling a fire at an Invercargill farm machinery dealership early this morning.

A fire service spokesman said the fire at the dealership in North Rd was "well-involved", but there were no reports of injuries.

It was snowing in Invercargill when firefighters were called to the scene just before 11.45pm, he said.

An hour later they were still fighting the fire and in "defensive mode" to prevent it spreading to other buildings.