a letter to his wife, P. M. Møller explained in October 1886, "The little star on the chimney is a memory of the night when I prayed for you and asked for a sign: If a star would appear in the gray and cloudy sky, it would mean that the Lord answers prayers." The same star later became the emblem of the Maersk Group. A.P. Moller–Maersk is structured into two main business segments: transport & logistics and energy. These two branches include several subsidiaries such as container shipping and related activities; APM Terminals; tankers, training, offshore and other shipping activities; oil and gas activities; retail activity; and shipyards, other industrial companies, interest in Danske Bank, etc. "Container shipping and related activities" is the largest business area for A.P. Moller–Maersk, providing almost half of the group's revenue in 2008. It comprises worldwide container services, logistics and forwarding and terminal activities under the brand names: Maersk Line, Safmarine, and Damco. For the first since 1996, Maersk has been overtaken by MSC, which has become the container line with largest shipping capacity. . Transport and logistics Maersk The largest operating unit in A. P. Moller–Maersk by revenue and staff (around 25,000 employees in 2012) is Maersk Line. In 2013, the company described itself as the world's largest overseas cargo carrier and operated over 600 vessels with 3.8 million twenty-foot equivalent unit (TEU) container capacity. As of January 2021, as the largest container fleet, it held 17% of the global TEU. In 2006, the largest container ship in the world to that date, the vessel , was delivered to Maersk Line from Odense Steel Shipyard. Since, seven other sister ships have since been built, and on 21 February 2011 Maersk ordered ten even larger container ships from Daewoo, the , each with a capacity of 18,000 containers. The first were delivered in 2013. There was an option for 10–20 more, and in June 2011, Maersk placed a follow-on order for a second batch of ten sister ships (to the same design with the same shipyard), but cancelled its option for a third batch of ten. As of February 2010, Maersk had an order book for new ships totalling 857000TEU (including options on the Triple E class); that backlog is larger than the existing fleet of the fourth-largest line, Evergreen Line. Maersk Line cooperated with the United States Navy on testing 7–100% algae biofuel on