Fire crews work to secure a sign on a building in Exhibition Street. Credit:Darrian Traynor

Firefighters abseiled down a building in Melbourne's CBD on Monday as they removed a Telstra sign which had been damaged by wind on the 45th floor.

The footpaths underneath the building on the corner of Exhibition and Lonsdale streets were cleared by police as the firefighters worked above.

The MFB's high-angle rescue crew managed to remove the dislodged Telstra sign, which was about 6 metres by 4 metres and made of canvas.