Wärtsilä, ship power system integrator, and IHI Marine United Inc. (IHIMU) of Japan, have concluded a co-operation agreement. Under the agreement, Contra-Rotating Propeller (CRP) systems developed by IHIMU will be incorporated into Wärtsilä's propulsion solutions used on board diesel-electric driven ships. The co-operation agreement mainly covers the European market, where the environmental demands on shipping operations are becoming increasingly stringent. The IHIMU CRP systems have been installed over a period of more than 20 years onboard VLCC and bulk carrier vessels.