The International Longshore and Warehouse Union (ILWU) appears to be closing in on a three-year contract extension with its terminal operator employers which would ensure dockworker stability up and down the U.S. West Coast     The ILWU said in a statement Friday afternoon it has completed voting on a proposed extension to its existing collective bargaining agreement with the Pacific Maritime Association (PMA), and early indications are that the extension will be approved by a 67 percent majority. The union will announce the official results of the vote on Aug. 4.    The current ILWU-PMA labor deal which was marked…