Nasdaq OMX, the parent company of the Nasdaq Stock Market, said the outage lasted six minutes — from 11:35 a.m. Eastern Daylight Time 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 had stock tickers PC through SPZ.
According to Nasdaq OMX's preliminary review, the outage was caused by a hardware failure on one the exchange's servers. A secondary system took over soon after. Wednesday's trading ended normally, Nasdaq said.
The outage is the latest technical difficulty to hit the exchange, which endured a three-hour trading outage on August 22. That outage was also blamed on the exchange's price quote disseminating system.
In Washington, Securities and Exchange Commission spokesman John Nester said the agency is in contact with the exchange and monitoring developments, as is its practice in these situations.
Business Writer Marcy Gordon in Washington contributed to this report.