When talking about the "PTT public company limited" visibility of State Enterprise "grade" that is considered a prototype "achievements" of State-owned enterprises and the success of privatization.
When speaking of "company PTT Public Company Limited ()" Everyone sees enterprise "grade" is considered the prototype for the "success" of the enterprise. And the success of privatization.
When talking about "the company PTT." everyone could see the enterprises. "Grade" is a prototype. "Success" of the enterprise, and the success of privatization.