What is the ruling on a salesperson selling for another company that offers the same product at a lower price than his own company, in exchange for a commission, after he first attempted to sell his own company's product?

The representative is an agent for his company in sales, and an agent is a trustee who is obligated to act in the most beneficial and advantageous way for his principal. The described scenario involves a betrayal of trust and a loss of benefit for the company. The representative is obligated to inform his company about market conditions and price variations.