757's are run by DHL International, which was a separate company to the old U.S. company, DHL Airways, Inc. DHL Airways, INC was bought by DeutshePost, the German Post office, a couple years ago. They then split the company into several different entities, since a U.S. Airline cannot be foreign owned. The airline portion, and employees who loaded planes, were split into Astar Air Cargo, under the control of one of DHL Airways' largest American shareholders. Van drivers were spun into a different company, and sales and service folks were spun into yet another company.
Then DeutshePost bought Airborne, and alone with it, ABX Air. They then fired all the DHL van drivers because the Airborne ones were teamsters, and the DHL ones were not. The teamsters had some good language in that contract apparently. All the Airborne vans were painted with DHL colors and Airborne basically was folded into DHL. So now, there are two U.S. Airlines hauling DHL material, ABX and Astar. They are being whipsawed against each other, from what I hear, in classic union-busting fashion by the Germans.