Method and system for block trading of securities. Embodiments of the present invention can provide an automated dealer system that formulates customized, risk-controlled, two-sided indicative quotations for block quantities of a security. A quotation can be delivered to requesting counterparties via a secured network or Web-based platform. The system can also allow counterparties to submit orders for block trades based on the customized quotations. A customized quote can be based on the size of the block and historical characteristics of the security. The quoting service can be customized to take into account a minimum premium to be charged for a trade, profitability considerations discounts, and time considerations.