This report analyses the relationship between the competence of the regulator and the competition authority in the sectors of natural gas and electricity in Lithuania. Since these sectors share similarities with the telecoms sector, it may be appropriate to rely on the national practice in telecoms. The decision of the regulator does not prohibit the competition authority to proceed with a separate investigation and to state an infringement of competition rules. The competition authority should at all times examine whether the regulator had jurisdiction and exercised it in order to eliminate a potential breach of competition rules.