How to become designated commercial agent for a company/entity?

Hello all,

With the commercial deals I have done, I continue to run into agents who have received a contract with rights to be the designated agents for this company in their state. How does one go about reaching out to a company to do so? For example, any property purchased or listed in your state companyA grants you rights to be their agent for that state! 

Thanks in advance. I have ideas about how to approach this, but as a "newer" agent I wanted to know what the deal is!!