WASHINGTON (Reuters) - The U.S. State Department has approved the potential sale of CH-47F Chinook helicopters and related equipment to Egypt for an estimated cost of $2.6 billion, the Pentagon said on Thursday.

       Egypt had requested to buy 23 CH-47F Chinook helicopters, the Pentagon said, adding that the principal contractor will be Boeing Helicopter Co.

       (Reporting by Katharine Jackson; Editing by Eric Beech)