Since they are morally responsible, there is a greater need for them to act in ethical manners than if their actions caused no harm to anybody.
One example could be international trade and the food industry. Ethically speaking, a lot of food from third-world countries is problematic because it is farmed using slave or child labor, or both. So if there were a major food company like Hershey’s which bought their cocoa through unethical channels, that company would be having a very negative effect on people who were being forced to farm cocoa beans. This would be an unethical act, and one that would effect society at large as well.
On the positive side, though, there are many companies who sponsor elementary schools when purchases or made, or who sponsor community-oriented events and initiatives. In this case, the organizations can be good moral agents, as well as “top corporate citizens” who have made sure that they act ethically as well as just out of a sense of what is economically good for their company (Ferrell, Fraedrich, Ferrell