Wärtsilä Corporation and Mitsubishi Heavy Industries of Japan have made a joint development agreement to design and develop a new low-speed marine diesel engine. The two companies see a potential in pooling their resources and experience to produce a new engine of 500-600 mm cylinder bore. Such engines are suitable for a wide variety of ship types, including bulkcarriers in the Handymax and Panamax sizes, large product tankers, container feeder vessels, and medium-sized reefer ships. The new engine is expected to meet the market needs for high efficiency, compactness and environmental requirements.

Today, Wärtsilä has its own range of low-speed marine diesel engines, with the Sulzer low-speed engines covering the power range of 5,000 to 80,000 kW. Mitsubishi also has its own range of UE low-speed marine diesel engines covering the power range of 1,120 to 46,800 kW, and also has long co-operated in the manufacture of Sulzer engines going back to an agreement signed in 1925. Over the years, Mitsubishi has notably been extensively involved in the building and testing of the first examples of new designed Sulzer low-speed engines. The new agreement takes this co-operation a step further to joint design and development.The project is led by a joint working group of engineers from both companies with supervision by a steering committee including senior management of the two companies. It is envisaged that the new engine would be built in Japan by Mitsubishi, Mitsubishi´s licensees and Wärtsilä´s licensees. In Korea and China, the engine will be built by Wärtsilä´s and Mitsubishi's licensees.