Electronic communications network linking the trading floors of seven registered exchanges to permit trading among them in stocks listed on either the N.Y.S.E. or A.M.E.X. and one or more regional exchanges. Through I.T.S., any broker or market-maker on the floor of any participating exchange can reach out to other participants for an execution whenever the nationwide quote shows a better price available. A floor broker on the exchange can enter an I.T.S. order to assure that he will get all of an offering or bid, instead of splitting it up with competing brokers.