The rating on Thai Oil Public Co. Ltd. (Thaioil) reflects the support the company receives from its operational integration with, and strategic importance to, state-owned oil and gas conglomerate PTT Public Co. Ltd. (PTT; BBB+/Stable/--). The rating also reflects Thaioil's favorable cost structure, flexibility in feedstock selection, and strong domestic market position. The company's financial ratios are somewhat better than what we would expect for the rating. Inherent industry risks and Thaioil's single-site and customer concentration risks partly offset these strengths. We assess Thaioil's business risk profile as "satisfactory" and its financial risk profile as "significant". We expect the company's credit protection measures to moderate in 2012 after an improvement in the previous year. An uncertain global economic outlook is