Without qualification, construction cannot be carried out, and the responsibility is very heavy. In addition, whoever wins the bid for the project will build it. Some engineering countries explicitly prohibit subcontracting and re-contracting, so new companies may not be able to build even if they are qualified. So:
The newly established company should sign a cooperation agreement with the winning company, set up a project department under the winning company, and construct in the name of the project department. The new company will pay the management fee to the winning company.