The FCO will assess whether the concentration leads to a significant impediment to effective competition (so-called SIEC test).

The FCO usually first identifies the product or services market(s) affected by the concentration and the geographic scope before assessing the competitive effects the deal will have on such markets. In applying the SIEC test, the FCO inter alia considers whether the notified concentration will create or strengthen a dominant market position. The German Competition Act presumes a dominant position to be a market share of at least 40%; however, this presumption can be rebutted. Furthermore, the German Competition Act presumes that a group of companies is collectively dominant if two or three companies together hold a market share of 50%, or four or five companies together reach a market share of two-thirds. Companies can rebut the presumption of collective dominance by demonstrating that there is substantial competition between them or that they do not have a superior market position in relation to other competitors outside the group.

Dominance is only one example of a significant impediment to effective competition, and the FCO can prohibit deals without establishing dominance if the transaction otherwise lessens competition.

The FCO may not block a concentration if the conditions for prohibition are met only in markets in which goods or commercial services have been offered for at least five years and in which the total domestic turnover in the last calendar year was less than EUR 20 million – unless (i) services in these markets are provided free of charge or (ii) the concentration requires clearance because the transaction value threshold (EUR 400 million) is reached.