Final answer:
The primary purpose for granting superseniority is to guarantee pay for time spent handling union business during working hours, while also providing an incentive for cooperation with management.
Step-by-step explanation:
The primary purpose for granting superseniority to highly skilled technical employees and union officials directly involved in contract negotiation or grievance handling is to guarantee pay for time spent handling union business during working hours.
This provision ensures that these employees will not incur any financial loss while engaging in union-related tasks. By protecting their income, the organization provides an incentive for cooperation between management and these employees.