The union said it was to take action on behalf of four of its members in relation to allegations of unfair dismissal and that wages had not been paid for September and October.
PBB was bought out of administration by Celinco in September.
Unite regional officer Ian Maidlow said: "We are about to run legal claims against this organisation, or offshoots of it, for breach of contract, unfair dismissal, protective award and unlawful deduction of wages."
Unite said it sent a letter to PBB managing director Simon Singleton dated 6 October requesting he confirm the basis on which he was entitled to lay off the employees.
The letter also asked Singleton to provide a copy of the relevant documentation on which he based his decision.
Unite said it has not yet received a reply to the letter.
Singleton said he has not received the letter, but declined to comment further.
Maidlow said: "The true owners of this company are hiding from their employees and the obligations they have to them. There appears to be constant buck-passing at relatively senior levels about who said what to who and why."
Unite assistant general secretary Tony Burke confirmed the union would be consulting with its legal advisors.
"We will support our members in the face of these alleged non payments and forced redundancies," he said.
Celinco declined to comment.
Unite to begin PBB/Celinco legal action
Unite has said it is to take legal action against Piggott Black Bear (PBB) and parent company Celinco over a series of alleged breaches of contract and unfair dismissal charges.
