Why are negotiating skills useful for managers? What should a manager do to become an effective negotiator?

Managers will inevitably be in positions where there are disagreements about courses of action to pursue or differences of opinion about what results are desired. In these types of situations, negotiation comes into play. In order to be effective in dealing with such situations, managers need to be effective negotiators. Successful negotiation occurs when issues of substance (i.e., the "content" issues) are resolved and working relationships among the negotiating parties are maintained or even improved in the process.
A manager can become a skilled or effective negotiator by learning to follow the rules of principled negotiation, which include the following: separate the people from the problem; focus on interests, not on positions; generate many alternatives before deciding what to do; and insist that results are based on some objective standard. A skilled negotiator also recognizes and avoids the following common negotiation pitfalls: falling prey to the myth of the "fixed pie"; non-rational escalation of conflict; overconfidence and ignoring others' needs; and too much telling and too little hearing.