Does a Shareholders’ Agreement Create an Irrebuttable Presumption of Acting in Concert?
Whether a shareholders’ agreement automatically and irrebuttably triggers the “acting in concert” qualification for mandatory bid purposes — selected European countries, 2025.
Analysis: Prof. Marco Ventoruzzo (Bocconi University) · Visualisation: ECGI
15 jurisdictions surveyed. Non-surveyed countries shown in grey. Hover over any surveyed country for details. The full comparative table is available below the map.
This visualisation shows a map of Europe and a comparative table examining whether a shareholders’ agreement creates an irrebuttable presumption of acting in concert for mandatory bid purposes. Fifteen European jurisdictions were surveyed. Italy is the only jurisdiction where the answer is yes. All other surveyed jurisdictions have rebuttable presumptions or require case-by-case assessment. The full comparative table with legal references is provided below the map.
Source: Prof. Marco Ventoruzzo analysis, 2025. “Irrebuttable” (iuris et de iure): no proof to the contrary is permitted once the triggering fact is established. Classification reflects the regime as of the survey date; the Italian irrebuttable presumption is subject to proposed legislative reform.
| Country | Irrebuttable presumption? | Type of regime | Key legal references |
|---|---|---|---|
| Austria | No | Substantive test on coordination aimed at acquiring or exercising control; no irrebuttable presumption arising from the mere existence of a shareholders’ agreement. | Übernahmegesetz (ÜbG); OGH case law |
| Belgium | No | Substantive definition of concert linked to the purpose of acquiring or maintaining control; no irrebuttable presumption triggered by a shareholders’ agreement alone. | Loi du 1er avril 2007 (Takeover Act); FSMA supervision |
| Denmark | No | Substantive definition aligned with Directive 2004/25/EC; case-by-case assessment by Finanstilsynet; no irrebuttable presumption from a shareholders’ agreement. | Kapitalmarkedsloven (Capital Markets Act); Bekendtgørelse om overtagelsestilbud |
| France | No | No irrebuttable presumption; case-by-case assessment based on a bundle of evidence (faisceau d’indices). Statutory presumptions exist only for specific relationships (parent/subsidiary, directors, etc.) and are rebuttable. | Art. L.233-10 Code de commerce; Cour de cassation case law |
| Germany | No | No irrebuttable presumption; substantive assessment of coordination aimed at control. BaFin distinguishes lawful collaborative engagement from acting in concert. | § 2(5) WpÜG; §§ 33 et seq. WpHG; BaFin guidance |
| Greece | No | Definition of “persons acting in concert” closely follows the Directive (cooperation to acquire control or frustrate a bid). Presumptions for controlled entities are rebuttable. | L. 3461/2006, Art. 2(e); L. 4706/2020; HCMC supervision |
| Ireland | No | Statutory presumptions of concert for specific categories (e.g., shareholders above threshold, directors) expressly rebuttable before the Irish Takeover Panel (“until the contrary is established to the satisfaction of the Panel”). | Irish Takeover Panel Act 1997, s. 8(d); Irish Takeover Rules 2.1 and 3.3 |
| Italy | Yes | Irrebuttable presumption (iuris et de iure). Participation in a shareholders’ agreement falling within Art. 122 TUF — even if the agreement is void — triggers “in every case” the qualification as acting in concert, with no possibility of rebuttal. Automatic joint liability for a mandatory offer under Art. 109 TUF. | Art. 101-bis(4-bis)(a) TUF; Art. 109 TUF; Art. 122 TUF; Consob Communications |
| Luxembourg | No | Substantive definition aligned with Directive 2004/25/EC; requires cooperation aimed at acquiring or exercising control; no irrebuttable presumption from a shareholders’ agreement. | Loi du 19 mai 2006 (transposing Dir. 2004/25/EC) |
| Netherlands | No | “Onderling overleg” (acting in concert) is assessed based on the content and purpose of the arrangement; no irrebuttable presumption from a shareholders’ agreement. | Art. 5:70 Wft; AFM guidance |
| Portugal | No | Presumptions of concerted action are rebuttable (ilisão) before the CMVM; parties may demonstrate that the agreement does not pursue common relevant influence. | Art. 20 Código dos Valores Mobiliários (CVM) |
| Spain | No | Rebuttable legal presumption (iuris tantum) where agreements aim at acquiring control; proof to the contrary is admitted. | RD 1066/2007; LMVSI (formerly LMV) |
| Sweden | No | Definition of acting in concert aligned with the Directive; presumptions for specific categories are rebuttable. The Swedish Securities Council (Kollegiet) assesses on a case-by-case basis. | Lagen om uppköpserbjudanden (LUA 2006:451); Swedish Takeover Rules |
| United Kingdom | No | Presumptions of concert for defined categories of persons, expressly rebuttable to the satisfaction of the Takeover Panel. | City Code on Takeovers and Mergers (definition of “acting in concert” and related presumptions) |
Key takeaway: Italy is the only jurisdiction among the 15 surveyed where participation in a qualifying shareholders’ agreement triggers an irrebuttable presumption of acting in concert, with automatic joint liability for a mandatory offer under Art. 109 TUF. In all other 14 jurisdictions, proof to the contrary is always available or, at a minimum, a case-by-case assessment by the competent authority is permitted. Source: Prof. Marco Ventoruzzo analysis, 2025.