Airlines established in the Czech Republic must be majority owned and effectively controlled by EU states and/or nationals of EU states, unless otherwise provided for through an international agreement to which the EU is a signatory.
"Article 4 - Conditions for granting an operating licence:
An undertaking shall be granted an operating licence by the competent licensing authority of a Member State provided that: [...]
(f) Member States and/or nationals of Member States own more than 50 % of the undertaking and effectively control it, whether directly or indirectly through one or more intermediate undertakings, except as provided for in an agreement with a third country to which the Community is a party; [...]" (Regulation (EC) No 1008/2008 on common rules for the operation of air services in the Community, Article 4(f))
Regulation (EC) No 1008/2008 on common rules for the operation of air services in the Community, Article 4(f)
[<a href="https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02008R1008-20201218">Reg</a>]