This is the security exchange system where broker-dealers negotiate directly with one another rather than through an auction market that is on the exchange floor. The trading in the OTC market takes place over computer and telephone networks that link brokers and dealers around the world. Both listed ant OTC securities, as well as municipal and U.S. government securities are traded in the OTC market.
See over-the-counter market.
The "inter-dealer" trading of shares, where a brokerage firm quotes a bid price and an asked price, at which it is willing to buy or sell shares.