related tradespeople; affiliated contractors
Refers to businesses or tradespeople connected to a particular industry or project, such as subcontractors, suppliers, or service providers.
Many related tradespeople are involved in this construction project.
Please keep in close contact with affiliated contractors.
下請け業者 specifically means subcontractor, while 関連業者 is broader and includes any related business or tradesperson.
Compound of 関連 (related) + 業者 (tradesperson, business).