Employees sometimes retract grievances. Often they have simply had a change of heart, for example realising that they have overreacted to a situation.
However, the withdrawal could be because of, for example, a fear of reprisals where another employee is the subject of the grievance.
The employer should therefore seek to ascertain the reason for the withdrawal, and provide reassurance to the employee where necessary. In some circumstances, it may be appropriate for the employer to follow up on the issues raised in the grievance even where the employee does not wish to pursue it.