Nasdaq OMX executives internally on Thursday pointed to a "connectivity" problem with competing electronic exchange NYSE Arca as the trigger to technical issues that led to a three-hour halt in trading of Nasdaq-listed stocks, according to people familiar with the matter.

"There was a connectivity issue between an exchange participant" and the Nasdaq-operated data feed that supplies US markets with information on stocks listed on the Nasdaq Stock Market, the exchange operator said in a statement issued Thursday evening.