Republic of Bulgaria; 4. reasons related to public interest, arising from the efficient use of the scarce resource, protection of the interests of users and universal service provision. (2) (Amended, SG No. 105/2011, effective 29.12.2011) The authorization shall be modified and supplemented under Item 4 of Paragraph (1) after written notification of the undertaking concerned, which may express an opinion within fourteen days after receipt of the notification. (3) (New, SG No. 105/2011, effective 29.12.2011) Where the authorization is modified and supplemented materially under Item 4 of Paragraph (1), the Commission shall conduct a public consultation according to the procedure established by Article 37 herein within thirty days. Article 116. The undertaking which has been granted an authorization may approach the Commission with a reasoned request to amend and supplement the authorization outside the cases covered under Article 115 (1) herein. The Commission shall examine the reasonableness of the request, shall judge the need of modifying and supplementing the authorization, and shall pronounce by decision within thirty days after receipt of any such request. Article 117. (1) The validity of an authorization for use of an individually assigned scarce resource as granted shall cease after withdrawal of the authorization as granted by the Commission in the following cases: 1. where an undertaking which has been granted an authorization for use of an individually assigned scarce resource - radio spectrum or geostationary orbital positions, has failed to fulfil any or all of the obligations thereof under Item 9 of Article 106 herein; 2. upon ascertainment of systematic violations of one and the same condition of the authorization as granted for use of the individually assigned scarce resource as provided; 3. upon systematic non-payment of the taxes due in connection with the authorization granted; 4. where, upon conduct of a check by the Commission, existence of any of the circumstances referred to in Item 3 (a), (b) and (c) of Article 84 (1) herein has been ascertained; 5. (new, SG No. 105/2011, effective 29.12.2011) an undertaking, which has been granted an authorization for use of an individually assigned scarce resource - radio spectrum, or geostationary orbital positions, has failed to fulfil any or all of the obligations thereof under Item 5 of Article 106 herein and has not submitted a request for transfer or lease of the radio spectrum provided for individual use according to the procedure established by Article 121 herein. (2) The validity of the authorization for use of an individually assigned scarce resource may be terminated in the following cases: 1. at a reasoned written request from a competent authority upon ascertainment of actions by the undertaking which jeopardize national security upon use of the individually assigned scarce resource as provided thereto by the authorization; 2. where the undertaking which has been granted an authorization declares existence of any of the circumstances referred to in Item 3 (a), (b) and (c) of Article 84 (1) herein; 3. at a reasoned written request from the undertaking which has been granted an authorization; 4. (amended, SG No. 17/2009) upon death of the natural person, upon liquidation or dissolution of the legal person or upon cessation of the activity of the sole trader: in the cases where authorizations have been granted thereto; 5. upon expiry of the period of validity of the authorization; 6. on the grounds of an obligation arising from a ratified international agreement which has entered into force and whereto the Republic of Bulgaria is a party; 7. after notification by the Council for Electronic Media of an effective decision on termination of the relevant radio or television broadcasting licence of the undertaking implementing electronic communications over existing and/or new electronic communications networks for analogue terrestrial broadcasting. (3) The decisions adopted by the Commission in pursuance of Item 1 of Paragraph (2) shall be