It said in a statement on its website it did not know what had caused the problem.

Stephan Beckert, an analyst with the US-based telecommunications market research firm TeleGeography, said the three affected cables were the most direct route for moving traffic between Western Europe and the Middle East.

"If those three cables were cut and are completely out, it would be a fairly significant outage," he said.

"It is going to cause problems for some customers. It's certainly going to slow things down," Beckert said, adding that he did not believe financial institutions would be hit hard.

"Generally speaking we find that they are extremely painstaking about making sure that they have redundant capacity," he said.

Officials with AT&T Inc and Verizon Communications, the two largest U.S.-based carriers, said that some customers in the Middle East had lost all service, while others were experiencing partial disruptions on Internet connections.

Verizon had rerouted some of its traffic by sending it across the Atlantic, then the United States, across the Pacific, and on to the Middle East.

A New York Stock Exchange spokesman said he was unaware of any disruptions in trading. Exchanges CME Group, and Intercontinental-Exchange said they had no disruption in their trading on Friday.