The Commission is extending the compliance dates for Rule 610 and Rule 611 of Regulation NMS under the Securities Exchange Act of 1934 ("Exchange Act"). Rule 610 requires fair and non-discriminatory access to quotations, establishes a limit on access fees, and requires each national securities exchange and national securities association to adopt, maintain, and enforce written rules that prohibit their members from engaging in a pattern or practice of displaying quotations that lock or cross protected quotations. Rule 611 requires trading centers to establish, maintain, and enforce written policies and procedures reasonably designed to prevent the execution of trades at prices inferior to protected quotations displayed by other trading centers, subject to an applicable exception. The Commission is extending the compliance dates to give automated trading centers additional time to finalize development of their new or modified trading systems, and to give the securities industry sufficient time to establish the necessary access to such trading systems.