In first-of-their-kind charges, the watchdog says that over an "extend period of time" beginning in 2008, Nyse sent out data through two of its proprietary feeds - Book Ultra and PDP Quotes - before sending it to the consolidated tape, violating SEC Regulation NMS.

The disparities in data release times - which ranged from single-digit milliseconds to multiple seconds - was partly down to an internal Nyse system architecture that gave one of the feeds a faster path to customers. This was compounded by a software issue in the system that sent data to the consolidated feed.

The SEC order criticises Nyse's "inadequate compliance efforts", finding that the compliance department was not involved in important technology decisions, including the design, implementation, and operation of market data systems.

The exchange also failed to retain computer files that contained information about transmission of market data, including the times that IT sent data to be included in the consolidated feed. This failure complicated Nyse's ability to determine when it experienced delays sending data and calculate their length.

The exchange and its parent, Nyse Euronext, have agreed to pay a $5 million penalty and bring in an independent consultant to conduct a review of their market data delivery systems.

Daniel Hawke, chief, market abuse unit, enforcement division, SEC, says: "The violations at Nyse may have been technological, but they were not technical. Robust technology governance is just as important to preventing investor harm as any other compliance or supervisory function."

In a statement on the issue, Nyse Euronext CEO Duncan Niederauer, says: "Nyse Euronext is committed to the highest standards of integrity and accountability. The timing differentials stemmed from technology issues, not from intentional wrongdoing by the exchange or any of its personnel."

You can read the full order here: