DHL and ABX Air Inc. have extended negotiations on a deal under which DHL would assume financial responsibility for leases of five Boeing 767-200 freighter aircraft that ABX is currently operating. ABX has been operating the aircraft on behalf of DHL under an existing agreement that expires in August 2010. The new arrangement, according to an 18 March memorandum of understanding (MOU), also would give DHL an option to lease up to four additional 767s. The March MOU provided that either party could terminate the MOU after 10 April if the parties did not enter into a definitive agreement by that date. That potential termination date was extended 9 April until end-April and was again extended last week until 15 May.