NEW YORK (AP) _ Merrill Lynch & Co., Goldman Sachs Group and Madoff Securities announced Tuesday the have formed an electronic trading system that will compete with traditional stock markets.

Their venture is called Primex Trading, and is the latest in a string of electronic communications networks that have popped up to offer investors another way to trade stocks.

Primex's gimmick is that it displays all stock orders to an electronic ``crowd'' of participants, who then compete, via computer, for the best price.

By contrast, the New York Stock Exchange, relies on a large group of brokers who gather on the floor of the exchange and call out their competing offers to buy or sell shares.

Systems like Primex, so far, have not yet been able to attract enough buyers and sellers to truly compete with the NYSE. But with high profile companies like Merrill Lynch and Goldman Sachs, two of Wall Street's biggest brokerages, behind the Primex, that could start to change.

The system is scheduled to go online by June 2000.