broker
Pronunciation: /ˈbrəʊkə/
noun
- a person who buys and sells goods or assets for others: the centralized lenders operate through brokersCompare with broker-dealer.
verb

Origin:
Middle English (denoting a retailer or pedlar): from Anglo-Norman French brocour, of unknown ultimate origin

The term broker was officially replaced in the UK Stock Exchange by broker-dealer in 1986, broker-dealers being entitled to act both as agents and principals in share dealings.