The blaze has engulfed the empty building at the junction of Princip Street and Lancaster Street with smoke billowing into sky and nearby roads.
West Midlands Fire Service has advised people nearby to keep windows shut and warned those heading to the Commonwealth Games through the city centre that their journeys may be disrupted.
In a statement the fire service said: “We have a number of fire engines at a large factory fire at Princip Street, Birmingham city centre.
“There is a large amount of smoke in the area-please close your windows to keep yourselves safe. If you’re heading into Birmingham for #B2022 (Commonwealth Games) please allow extra travel time.”
Fire crews were called at 6.47am, with nine fire engines and two aerial platforms – crewed by 50 firefighters – called to the scene.
Two crews from Aston were joined by firefighters from Hansdworth, Bournebrook, Wood End, Smethwick, Erdington, Perry Barr and Hay Mills.
Speaking shortly after 9.15am, a fire service spokeswoman said: “We are expected to be there for a while but good progress is being made at the moment.
“The fire is contained to just that building.”
In an update shortly after 12.30pm, the fire service said: “We’ve made good progress and the fire’s now largely under control.
“Our resources at the scene have been scaled down, but we still have a number of firefighters and vehicles there.
“Most roads have now reopened, except a slip road where our crews continue to work and manage the incident.
“The cause of the fire is yet to be determined – our investigators will be working on this over the coming days.”
West Midlands Police has shut a number of surrounding streets with Vesey Street, Princip Street and Price Street at the junction of New Town Row outbound from Lancaster Circus all closed to traffic.
At around midday police said New Town Row from Newtown Middleway into city to Lancaster Circus had fully reopened, along with New Town Row from James Watt Queensway via the underpass is also open again.
However, the slip to join New Town Row out of city from Lancaster Circus/St Chads Queensway remains closed.
The A34 has also been closed from the tunnels on Lancaster Circus Queensway to junction of New John St West, for inbound and outbound traffic because of the smoke plume.
National Express West Midlands has said that services 33, 51, 907, 934, 935, 936, 937 and 997 have all been diverted diverted via Newtown Middleway, Dartmouth Circus, Aston Road, Corporation Street and Lancaster Circus in both directions.
