As expected, eight private trading networks formally announced an agreement Thursday to link their after-hours systems. But investors may have to wait a while; the accord is vague and it's uncertain how quickly the integration would take place.
The rival electronic systems--including Instinet, Island, Archipelago, Bloomberg Tradebook and BRUT--have signed a non-binding letter of intent to make prices of trades done by their customers visible to investors on other systems. That information is critical, because investors base their buy and sell orders in part on a stock's last trade price.
