Unfavorable industry conditions will continue to hamper the earnings of Thailand-based PTT Global Chemical Public Co. Ltd. (GC) over the next two to three years. However, the impact of lower earnings on the petrochemical producer's leverage will be moderate given the absence of sizable capital spending post 2020. On April 14, 2020, S&P Global Ratings revised its outlook on GC to negative from stable. We also affirmed our 'BBB+' long-term issuer credit rating on the company and our 'BBB+' issue ratings on the US$1 billion senior unsecured notes issued by GC and GC Treasury Center Co. Ltd., a financial subsidiary. The negative outlook mirrors that on the local currency rating on PTT and reflects mounting pressure on the parent's creditworthiness.