By Diane Bartz WASHINGTON (Reuters) -A U.S. Senate antitrust panel will hold a hearing on the lack of competition in the ticketing industry after Ticketmaster’s problems last week managing the sale of Taylor Swift tickets, Senator Amy Klobuchar, chair of the panel, said on Tuesday. Senators Klobuchar and Mike Lee, the top Republican on the committee, did not provide a date for the hearing or a list of witnesses. “The high fees, site disruptions and cancellations that customers experienced shows how Ticketmaster’s dominant market position means the company does not face any pressure to continua…