US regulators said they were postponing key rules which will change the US securities trading landscape amid concern on Wall Street over technical issues. The delay gives the New York Stock Exchange 17 more months to seize a competitive advantage over electronic rivals.

The delay by the Securities and Exchange Commission had been widely anticipated, but it is longer than many in the financial industry had expected. The regulation was supposed to be enforced by late June but will now not come into effect until October 2007.