Fitch Ratings in Thailand has affirmed refining and petrochemical company Thai Oil Public Company Limited's (TOP) national long-term rating at "AA-(tha)" with a stable outlook after the company announced its final investment decision on its clean-fuel project (CFP).

Fitch Ratings (Thailand) has affirmed an “AA-” national long-term rating and senior unsecured national rating for refining and petrochemical firm Thai Oil, while giving it an “F1+” national short-term rating.