For a project manager, how significant is it to participate or get involved in the bidding stage?

Project Manager, the name itself describe how important role to manage the project... Bidding is core of the project, where it should to the financial of the firm involved. The participation of the engineer, midlevel executives not aware of the financial citation of the firm PL statement but project manager does... meanwhile, significantly participation of PM @ bidding stage will add more efficient at the time of preparation itself... so both in technically and in practically it is profit to the company if PM involved...