[ REPUBLIC OF ANGOLA Article 9 (Exploitation license) 1. The holder or usufructuary of a patent may grant a license to exploit the patent by means of a contract, which shall set out the conditions for this exploitation. 2. Unless otherwise provided, the rights obtained by means of an exploitation license may not be alienated without the authorization of the holder or usufructuary of the patent. Article 10 (Deprivation of a patent) Where the public interest, in particular the interests of national security, health or the development of vital sectors of the national economy, so require it, the Council of Ministers may decide that an invention should be exploited by a State body or by a third party designated by the relevant supervisory minister, without the consent of the patent holder, in return for payment of fair compensation. Article 11 (Compulsory license to exploit an invention) 1. Save in the event of proven force majeure, a patent holder who has not begun to exploit an invention in Angola within three years of the grant of the license, or who has interrupted the exploitation for a period of more than one year, shall be bound to cede the exploitation license to a requesting third party. 2. For reasons of public interest, a compulsory, non-exclusive license to exploit an invention that has fallen into disuse, or the effective exploitation of which does not meet market needs, may also be granted to a third party. 3. An industrialized invention that has been substituted by importation shall not be deemed to be effective exploitation, save in the event of agreements to which Angola is party. 4. Where an application for a compulsory license has been filed, the patent holder shall be notified thereof within a period of 90 days to enable him to present a challenge and to initiate administrative or legal proceedings, as appropriate, to defend his invention. 5. The beneficiary of a compulsory license must begin the effective exploitation of the invention in Angola within a period of 12 months from the grant of said license, and may not interrupt the exploitation for more than one year.