The abuse principle applies to the dominant positions, according to which abusing rather than having a dominant position is prohibited. Under the Competition Act, dominant positions are deemed to be held on the relevant market by persons which are able to pursue their business activities to a large extent independently of other market participants substantially without the need to take into account the market reactions of their suppliers, competitors, customers and other trading parties when deciding their market conduct. To put it in another way it means, that the undertaking have a significant market power, so that its dominant position is sustainable in a long term and that is why it is capable of raising prices and excluding competitors from the market, as well as influencing the level of the total output and the price on the market. An undertaking having a dominant position does not mean that there is no possibility to compete; it simply means that the undertaking concerned has a leading role on the market.

In the background of the most harmful practices of the undertakings having a dominant position there are strategies, the object of which is further to distort the weak competition by excluding competitors, hindering competitors- expansion or deterring them from efficient competition. The market behaviours intending to exclude competitors can have different forms, such as refusal to contract without justification, tying, forcing exclusive contracting or putting into practise certain pricing strategies that result in the exclusion of competitors or in the reduction of their ability to expand or compete actively.

The other kind of abuse is the adoption of exploitative strategies, the direct aim of which is to get higher profits or to force the other party to accept undesired services or disadvantageous contract conditions.