Trading on the New York Stock Exchange (NYSE) has resumed following a three-hour outage officials blame on a technical glitch.

The halt occurred at about 11:30 local time on Wednesday and the exchange immediately issued a statement saying it was experiencing a "technical issue" that it was working to resolve as quickly as possible.

Trading resumed at 15:30 local time, shortly before going to to close for the day.   

Earlier, the White House and the US Treasury Department said they were monitoring the "ongoing issue" and President Barack Obama has been briefed on the matter. But Homeland Security Secretary Jeh Johnson said technical problems reported by both United Airlines and the New York Stock Exchange were apparently not related to "nefarious" activity.

(1 of 3) The issue we are experiencing is an internal technical issue and is not the result of a cyber breach.

— NYSE (@NYSE) July 8, 2015

Earlier on Wednesday, both the Wall Street Journal (WSJ) and United Airlines also said they had experienced technical issues.  

The Federal Aviation Administration grounded all of United's flights following a systemwide computer glitch, which was resolved, the agency said. The grounding order began at 08.00 and ended at 09:47 local time.

About 260 flights were delayed, or 12 percent of all United's flights, according to website FlightAware, while seven flights werecancelled.

Iin a statement, United said: "We are recovering from a network connectivity issue this morning and restoring regular flight operations."

No additional details were available on what caused the glitch. The WSJ also later returned to normal service.

Source: Agencies