Summarize <m> Circle Line </m> in the following article:

For nearly two decades, city officials have hoped to see Pier A, a historic landmark at the northern edge of Battery Park, revived as a tourist attraction on the downtown waterfront. But the latest attempt to make commercial use of the 120-year-old pier is bogging down in a dispute between the city and an ambitious ferry operator.
The operator, New York Waterway Tours, planned to start offering hourly harbor cruises from the pier next week. But the city's Economic Development Corporation has refused to grant permission to reopen the pier, which is leased to a company controlled by one of the owners of the tour-boat operator.
The man behind the plan for the harbor cruises is William B. Wachtel, a Manhattan lawyer with designs on reviving the city-owned Pier A as a transportation center. He hopes it will serve as a hub for commuters traveling to and from New Jersey as well as tourists to the Statue of Liberty and Ellis Island.
His efforts are being closely watched by competitors in the city's small but contentious ferry industry.
''<m> Circle Line </m> continues to support efforts to upgrade Pier A, and though we have seen activity of a sightseeing business, we are not aware that it has received approval from appropriate agencies,'' said J. B. Meyer, the president of Circle Line Harbor Cruises, another tour operator.
Mr. Wachtel controls Wings Point Associates, which is leasing the pier, and the BillyBey Ferry Company, which he created a year ago to bail out the struggling operator of the Waterway ferries. BillyBey owns half of the Waterway fleet and half of an excursion business, New York Waterway Tours.
Last week, workers for the tour company started gearing up to start hourly cruises of the harbor from the pier. A schedule for the cruises, beginning April 14, appeared on Waterway's Web site and a trailer that would serve as a ticket office appeared at the edge of Battery Park. Other boat operators reported seeing boats making test runs from the pier. A spokesman for the United States Coast Guard, Petty Officer Mike Lutz, said yesterday that the Coast Guard had granted a permit to Waterway for excursion cruises to operate from Pier A beginning around April 14.
But there is a hitch: Wings Point and the city have been tied up in litigation over the progress of the renovation of Pier A for years and officials of the development corporation are not willing to cooperate until the lawsuits are settled. Janel Patterson, a spokeswoman for the development corporation, said this week that ''we are in workout negotiations with the leaseholder'' and added that ''we also advised them that it's premature for them to advertise or promote ferry service from Pier A.'' But two days later, Waterway was still advertising that cruises would begin on April 14.
Pat Smith, a spokesman for New York Waterway Tours and its owners, declined to say whether the company would run the tours without the city's consent. ''A final decision has not been made'' about operating sightseeing boats or commuter ferries from the pier, he said.
The dispute with the city has also threatened Mr. Wachtel's plan to run commuters to and from the pier. Waterway filed an application with the Army Corps of Engineers last year seeking permission to anchor barges alongside the pier so that ferries could dock perpendicular to it.
That proposal drew objections from other boat operators, including officials of New York Water Taxi and the Circle Line company that ferries tourists between Battery Park and the Statue of Liberty. Water Taxi, controlled by Douglas Durst, the Manhattan property developer, is Waterway's closest competitor in the harbor.
But Circle Line has the most to lose if Mr. Wachtel succeeds. Wings Point has been negotiating with the National Park Service to move the ticketing and screening operations for Statue of Liberty ferry passengers to Pier A from Battery Park. Circle Line's longstanding contract to operate ferries to the statue and Ellis Island is scheduled to expire in less than a year and Mr. Wachtel has said he may bid for it.