Trading glitch, again, for Nasdaq

NEW YORKThe Nasdaq Stock Market says that one of its trading systems had a brief outage, but the problem was resolved and trading was not affected.

Nasdaq OMX, the parent company of the Nasdaq Stock Market, says the outage lasted six minutes - from 11:35 a.m. EDT (1535 GMT) to 11:41 a.m.

The outage occurred in one of Nasdaq's quote dissemination channels, which are used to provide real-time price quotes on stocks. The companies affected by the outage have stock tickers PC through SPZ.

The outage is the latest technical difficulty to hit the exchange, which endured a three-hour trading outage on Aug. 22. That outage was also blamed on the exchange's price quote disseminating system.

Last year, the exchange played a role in the botched IPO of Facebook. Investors were left unsure of whether their orders had been filled for hours after trading began, watching helplessly as the price soared and then plunged. The exchange ultimately paid a $10 million fine in a settlement with the Securities and Exchange Commission.

In 2010, a so-called flash crash left panicked investors gasping when the Dow lost over 600 points over the course of five minutes, only to recover quickly. A joint report by the SEC and the Commodities Futures Trading Commission later described a market "so fragmented and fragile that a single large trade could send stocks into a sudden spiral."