The blaze broke out in the TRC Receiving Station, which feeds electricity to most parts of commercial centre Lal Chowk and adjoining areas, around noon, a spokesman of the Fire and Emergency Services said here.
The fire started from a room in the upper portion and engulfed the building, he said.
However, it was brought under control by fire brigade personnel, limiting the damage to the building, he said, adding that no one was injured in the incident.
The cause of the fire is being ascertained, he said.