The flame was brought under control after two hours of fire fighting, Fire Services Minister Javed Khan, who visited the spot, said.
Fire department sources said 20 fire tenders had been rushed to the spot after fire started in the seventh floor of the building at around 10.30 AM.
"Fire fighters, armed with masks and oxygen cylinders, entered the core area of the fire," a fire brigade officer said. He said proper enquiry would be conducted to ascertain the cause of fire.
There was no reports of any casualty, he said. Panchayat Minister Subrata Mukherjee, whose office is located in the building, said that his room was damaged by the fire.
Asked about the extent of damage, Mukherjee said that even if one computer was damaged, lots of documents would get lost.