Munro left Barrhead in November last year, nine months after selling the company to US travel brand Travel Leaders Group.
His lawyer, Stephen Miller of Clyde & Co, confirmed to TTG Munro is suing the company for unfair dismissal and unpaid wages.
An employment tribunal hearing on the case expected to take place later this month.
Miller said: “Bill is hoping that the employment tribunal decides to reinstate him to his position.”
TTG has approached Barrhead Travel for comment.