broker
noun /ˈbrəʊkə(r)/
  /ˈbrəʊkər/
 - a person who buys and sells things for other people
- Ask advice from an insurance broker.
 - a broker for the company
 
Oxford Collocations Dictionaryadjective- credit
 - insurance
 - mortgage
 - …
 
- act as
 - be
 
- broker between
 - broker for
 
 - (also stockbroker)a person or an organization that buys and sells shares for other people
 - broker (between A and B) a person who arranges the details of an agreement between two groups or countries that disagree or oppose each other 
- He offered to act as a broker between the rebels and the government.
 
Extra Examples- He acted as broker between the two opposing sides.
 - He used his position to establish himself as a power broker.
 
 see also honest broker, pawnbroker, power broker 
Word OriginMiddle English (denoting a retailer or pedlar): from Anglo-Norman French brocour, of unknown ultimate origin.