Airlines established in Denmark 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. An aircraft may not be registered in Denmark unless it is predominantly owned by Danish nationals or by companies or other entities controlled by Danish nationals. Cabotage is reserved to national carriers.
"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))

******

"§ 7. 
An aircraft can only be registered in Denmark,
1) when it has a Danish owner, and the owner is resident or domiciled in Denmark or in a state where the person in question cannot be the registered owner of an aircraft due to his nationality,
2) when the aircraft is owned by EU or EEA nationals or EU or EEA companies, etc. (legal persons), insofar as these are covered by the rules of the European Union, or
3) when the aircraft is owned by a person domiciled in Denmark and the aircraft is used with a place of departure in Denmark.
PCS. 2. As a Danish owner is considered
1) the Danish state and institutions controlled by the state,
2) Danish municipalities,
3) Danish citizens,
4) foundations domiciled in Denmark, the management of which consists exclusively of Danish citizens or persons covered by subsection (1). 1, Nos. 2-3,
5) associations and similar associations based in Denmark, where at least half of the members are Danish citizens or persons covered by subsection. 1, Nos. 2-3,
6) public limited companies and other companies with limited liability when the predominant number of participants are Danish citizens or persons covered by subsection (1). 1, nos. 2-3, and the company is subject to the full control of these participants, and
7) public limited companies, which exclusively have a Danish board of directors and executive board based in Denmark.
PCS. (3) The Minister of Transport, Building and Housing may in special cases allow an aircraft that is predominantly used with a place of departure in Denmark to be registered, even if the conditions in subsection (1) apply. 1 is not met.

§ 77. Permission for the carriage of passengers, mail and goods may, when the carriage only takes place between places within the realm, only be granted to the person who fulfills the conditions in § 7, para. 1, for registration of aircraft in this country set conditions.
[...]"
(Aviation Act (No. 1149 of 13/10/2017), last amended by Act No. 2073 of 21/12/2020, §§ 7 and 77 [google translation])
Regulation (EC) No 1008/2008 on common rules for the operation of air services in the Community, Article 4(f)
Aviation Act (No. 1149 of 13/10/2017), last amended by Act No. 2073 of 21/12/2020, §§ 7 and 77
[<a href="https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02008R1008-20201218">Regulation</a>],[<a href="https://www.retsinformation.dk/eli/lta/2017/1149">Act</a>]