<![CDATA[The coal transportation service industry requires companies not only to provide high-quality transportation services but also to implement business diversification strategies to enhance customer trust and satisfaction. PT Andhika Lines, as a coal transportation service provider, faces increasing competition in maintaining long-term customer relationships while improving service quality and business sustainability. This study aims to analyze the effects of Coal Transportation Services and Business Diversification on Customer Satisfaction, with Customer Trust serving as a mediating variable. This research employed a quantitative approach using a survey design involving 110 respondents who were customers of PT Andhika Lines. Respondents were selected using a purposive sampling technique. Data were collected through a five-point Likert scale questionnaire and analyzed using Structural Equation Modeling–Partial Least Squares (SEM-PLS). The results indicate that Coal Transportation Services have a positive and significant effect on Customer Trust (β = 0.284; t = 2.324; p = 0.010) and Customer Satisfaction (β = 0.411; t = 2.387; p = 0.009). Business Diversification also has a positive and significant effect on Customer Trust (β = 0.517; t = 4.442; p = 0.000) and Customer Satisfaction (β = 0.283; t = 2.523; p = 0.006). Furthermore, Customer Trust positively and significantly influences Customer Satisfaction (β = 0.295; t = 2.110; p = 0.018), while significantly mediating the relationship between Coal Transportation Services and Customer Satisfaction (β = 0.084; t = 1.868; p = 0.031), as well as between Business Diversification and Customer Satisfaction (β = 0.153; t = 1.821; p = 0.035). The findings reveal that Business Diversification is the most influential variable affecting Customer Trust, with a path coefficient of 0.517, while Market Expansion is the most representative dimension (loading factor = 0.962) represented by indicator X2.7 (loading factor = 0.912). Meanwhile, Empathy is the strongest dimension of the Coal Transportation Services variable (loading factor = 0.943) with indicator X1.10 (loading factor = 0.944). These findings suggest that improving customer satisfaction at PT Andhika Lines depends on expanding market coverage, delivering customer-oriented services, strengthening trust through service integrity, and maintaining long-term relationships as a source of sustainable competitive advantage.]]>
