According to Rule 24 of the European Patent Convention (EPC) Implementing Regulations (IR),

A licence in respect of a European patent application shall be recorded  
 

(a)
as an exclusive licence if the applicant and the licensee so request; 

(b)
as a sub-licence where it is granted by a licensee whose licence is recorded in the European Patent Register.

Prepared by European Patent Registration and Consulting Services
prov. by. Lawyers Antevski member of ARI International Law & Trade
www.european-patent-registration.com [1]
www.facebook.com/patent.registration.europe [2]