The appeal, which was filed in May, had challenged the Mexican Football Federation's (FMF) decision to continue with the suspension of promotion and relegation for the 2025-26 season.
The suspension was originally introduced in the 2019-20 season during the COVID-19 pandemic for a period of six seasons.
"After examining the evidence, the CAS Panel concluded that the FMF had always determined to suspend the system until the conclusion of the 2025-2026 season, which was made clear to the clubs when the decision was taken," CAS said in a statement.
The panel found that the FMF's decision aligned with the original agreement made in April 2020.
The clubs that appealed believed that the FMF and some Liga MX clubs were pushing to make the suspension permanent, keeping a closed league model similar to Major League Soccer in the United States.
Ten clubs had initially joined the appeal but four - Atlante, Cimarrones de Sonora, Alebrijes de Oaxaca and Jaiba Brava - later withdrew. That left six clubs - Atletico La Paz, Atletico Morelia, Cancun, Mineros de Zacatecas, Venados and Leones Negros - to proceed with the appeal.