Are you running Microsoft Dynamics CRM SBE v3.0?
The Knowledge Base

Tracking the Competition

One of the features that many a firm forgets about is the tracking of competition. In Microsoft Dynamics CRM you can build and then associate complete competitor profiles against any given opportunity. As you work the opportunity you can also unassociate competitors as perhaps they become less of a threat.

In Sales, Opportunities : Open an opportunity

In Sales, Competitors - Use the feature ADD Existing Competitor

Save and Close - It is that easy