Those markets include a stock exchange operated by the International Securities Exchange
The NYSE, the largest U.S. stock exchange, and ISE, the largest U.S. electronic options exchange, both declined to comment.
The regulations, called Reg NMS, or Regulation National Market System, some of which come into effect on Monday, would require automated, or "fast," markets to route orders according to the best available price.
NYSE has requested the deadline be pushed back to April 5 from March 5 for its obligation to route orders as required by new regulations to the International Stock Exchange and NASD Alternative Display Facility participants, which include Direct Edge, LavaFlow, and Track Data Securities according to the NASD Web site.
NYSE had requested in January that a Feb. 5 deadline for the regulations be delayed until March.