CHARLESTON, S.C. — An administrative law judge says Boeing broke national labor law when a human resources manager at its North Charleston plant told a mechanic not to talk about unionizing during working time.

The Post and Courier of Charleston reported Sunday that Judge William Nelson Cates says Boeing can’t prohibit employees from discussing the union while allowing discussion of non-work-related matters during working time.

Cates ordered Boeing to stop the practice and also required the manufacturer to post a notice that notifies employees of their right to organize.

A Boeing spokeswoman said the company is disappointed with the decision and disputes the findings.

Representatives of the International Association of Machinists and Aerospace Workers brought the unfair labor practice charge on behalf of the mechanic this spring.