Outside of the six crucial skills utilized by the Business Analyst, there are many other additional skills that certain BA roles will leverage. Here is a quick list of some of the most important ones.

• Decision-making: Ability to utilize information to decisively make a decision after weighing multiple alternatives.
• Technical aptitude: High comfort level with various technologies and the ability to learn new software quickly.
• Documentation: Write clear and concise documentation that accurately represents what was discussed or learned.
• Visual modeling: Visually depict complex thoughts and processes in diagrams and models (IE - process flowcharts, wireframes, use cases, etc.)
• Relationship-building: Ability to forge and maintain strong positive bonds with people at various levels of the organization (users, managers, executives).
• Self-managing: Independently, and many times proactively, manage tasks, projects, and deadlines. Ultimately, do what you are supposed to do even when no one is watching.
• Emotional intelligence: To be aware of and in control of one's emotions and reactions so as to handle situations with good judgment and attitude.

This last one isn't really a skill but is important to mention none-the-less. 

• Thick skin: Ability to receive feedback, without getting defensive or taking it personally.