The bureau is looking into allegations of an anti-competitive agreement among construction firms relating to a wide range of contracts.
Bureau spokeswoman Gabrielle Tasse says the contracts involved the building of public parks and squares and the repair of sidewalks, pipes, streets and sewers.
Such contracts have been the subject of previous testimony at Quebec's corruption inquiry, which has been exploring bidrigging and inflated contracts.
The bureau has previously said it has been keeping tabs on the Charbonneau Commission and would not hesitate to investigate when necessary.
Tasse says there is no evidence of wrongdoing and that investigators are at the stage of gathering information.
There are reports that more than a dozen businesses are being raided, but Tasse says she can't say how many are being targeted.
Also on HuffPost