The law of public takeovers

Scope, the mandatory offer and its exceptions

The Swiss law of public takeovers applies to public purchase offers for equity securities of companies with their registered office in Switzerland whose equity securities are at least partly listed in Switzerland, and of foreign companies whose equity securities are mainly listed in Switzerland. Swiss law may be disapplied where it conflicts with foreign law that offers equivalent protection to investors.¹ The rules cover voluntary offers as well as mandatory offers, exchange offers as well as cash offers, together with the repurchase by a company of its own shares, which is treated as a public offer where it exceeds certain limits.

The central provision is the mandatory offer. Anyone who directly, indirectly or in concert with third parties acquires equity securities and thereby, together with the securities already held, exceeds the threshold of 33⅓ per cent of the voting rights of a target company, whether or not those rights can be exercised, must make an offer to acquire all listed equity securities of the company. Target companies may raise this threshold in their articles of association to up to 49 per cent of the voting rights, a clause known in practice as opting up.² They may also exclude the mandatory offer altogether. A company may adopt such an opting-out clause before the listing of its equity securities. It may also adopt one at any later time, provided that the adoption does not unfairly prejudice shareholders within the meaning of the Civil Code.³

The mandatory offer protects minority shareholders when control changes hands. They are given the opportunity to leave the company at a fair price instead of remaining minority investors under a new controlling shareholder. The opting-out clause reflects the opposite concern: the protection of companies with a controlling founding family or anchor shareholder that wish to retain the freedom to sell control without being obliged to extend the offer to everyone. Many Swiss companies introduced opting-out or opting-up clauses around the entry into force of the takeover rules in 1998. Some of them still carry these clauses today.

The Sika case

The practical significance of the opting-out clause became visible in the dispute over Sika, the construction chemicals group based in Baar in the canton of Zug. In December 2014 the Burkard family, descendants of the company’s founder Kaspar Winkler, announced that they would sell their holding company Schenker-Winkler Holding to the French group Saint-Gobain for CHF 2.75 billion. The family held about 16 per cent of the capital but, through registered shares with a lower nominal value, about 52 per cent of the voting rights. Because Sika’s articles contained an opting-out clause, Saint-Gobain would have acquired control without having to make an offer to the public shareholders. The board of directors and a group of institutional shareholders, including the Bill and Melinda Gates Foundation and Cascade Investment, opposed the transaction.⁴

The Takeover Board, FINMA and finally the Federal Administrative Court, in a judgment made public in September 2015, confirmed that Saint-Gobain was entitled to acquire the family’s stake without making an offer to the public shareholders, because the opting-out clause was valid. The board of Sika had meanwhile restricted the voting rights of the family’s holding company at the general meetings. In October 2016 the Cantonal Court of Zug upheld these restrictions and ruled that the family could not sell its voting majority without the approval of the board.⁵ The dispute ended in 2018 with a settlement under which Saint-Gobain acquired a minority stake in Sika, the dual share structure was abolished and the opting-out clause was removed from the articles.⁶

The case shows how the Swiss system distributes the protection of minority shareholders between takeover law and corporate law. Takeover law, as interpreted by the Takeover Board and the courts, respected the choice made in the articles. Corporate law, applied by the civil courts, gave the board instruments to defend what it regarded as the interest of the company. For practitioners advising controlling shareholders of Swiss listed companies, the lesson is that an opting-out clause does not guarantee a frictionless sale of control where the board and other shareholders are determined to resist.

The minimum price and the best price rule

Where a mandatory offer must be made, the price must be at least equal to the higher of two amounts: the stock exchange price and the highest price that the offeror has paid for equity securities of the target company in the preceding twelve months.⁷ The stock exchange price is determined as the volume-weighted average price of the last sixty trading days before the publication of the offer or its pre-announcement. Under the best price rule, if the offeror acquires equity securities at a price above the offer price between the publication of the offer and six months after the expiry of the additional acceptance period, it must extend that price to all recipients of the offer.⁸

Until 2013 the minimum price rule contained an important exception. The offer price then had to amount to no less than 75 per cent of the highest price paid by the offeror in the preceding twelve months. An offeror could therefore pay a controlling shareholder a control premium shortly before the offer and offer the public shareholders up to a quarter less. Parliament abolished this possibility in the revision of the Stock Exchange Act that entered into force in 2013. The legislator reasoned that control premiums violated the principles of equal treatment and transparency, disadvantaged minority shareholders and placed the Swiss market at a competitive disadvantage, since most European countries had abolished them under the EU Takeover Directive.⁹ Since then, the rule has been strict: every shareholder receives at least the highest price paid by the offeror in the preceding year.

Offerors who acquire more than 90 per cent of the voting rights may squeeze out the remaining minority by a merger in which the minority receives compensation in cash. Where they hold more than 98 per cent, they may ask the court to cancel the remaining equity securities against payment of the offer price. These mechanisms allow a successful offeror to take the target private and to delist it from the exchange, a common outcome of takeovers by private equity funds and industrial acquirers.

The Takeover Board and the procedure

The Swiss Takeover Board (Übernahmekommission, UEK, in French Commission des OPA, COPA) examines compliance with the provisions on public takeovers case by case. It has its seat in Zurich at the Stockerstrasse and publishes its decisions, together with its annual activity reports, on its website.¹⁰ The Board is composed of experts appointed by FINMA, typically lawyers, bankers and corporate executives with experience in public offers, who are supported by a small secretariat. Its procedure is fast. Most decisions are issued within days, since an offer cannot proceed while legal questions remain open.

Decisions of the Takeover Board may be appealed to FINMA, where the Takeover and State Liability Committee of the Board of Directors rules on appeals. FINMA’s decisions may in turn be appealed to the Federal Administrative Court, which is the final instance in these matters.¹¹ Before publication of an offer, a review body, usually an audit firm or a bank, must confirm that the offeror has the necessary financing in place and that the offer complies with the law. Qualified shareholders holding at least 3 per cent of the voting rights of the target company may participate in the proceedings as parties.

The Board has developed a detailed practice on questions that the Act leaves open. It has established rules on the independence of board members who assess the offer, on the fairness opinions that boards obtain and on transaction agreements between offeror and target. Its practice on exclusivity and no-shop clauses has tightened in recent years. The Board has refused to accept definitions of a “superior offer” that would prevent the target board from evaluating competing bids freely, insisting that the board can take into account the interests of all stakeholders and must remain free in its evaluation.¹²

The takeover market in recent years

The number of public offers for Swiss listed companies has fallen in recent years. In 2025 only two public tender offers were announced, one of them by an offeror that already held more than 80 per cent of the target. The largest Swiss corporate transactions of the year used other structures: the Holcim group separated its North American business as Amrize through a spin-off, while the insurers Helvetia and Baloise combined through a statutory merger under the Merger Act, which is not subject to takeover law in the same way as a tender offer. The decline in the number of offers reflects the high valuations of Swiss companies, the reduced number of small and medium-sized listed companies and the preference of some acquirers for negotiated structures. It also reflects the dominance of a small number of very large companies on the Swiss exchange, whose size places them beyond the reach of most potential acquirers.

The Board nevertheless remains an institution of considerable authority. Its decisions shape the conduct of offerors and targets far beyond the individual case. Its practice is followed closely by the law firms and investment banks of Zurich and Geneva that advise on public transactions. The concentration of this expertise in Zurich, where the Board, the exchange and most of the advisers are based, is one of the less visible strengths of the financial centre.

Notes

1. FinfraG, Art. 125 paras. 1–2, https://www.droit-bilingue.ch/de-fr/9/95/958.1-125-134.html. ↩
2. FinfraG, Art. 135 para. 1, https://www.droit-bilingue.ch/de-fr/9/95/958.1-135-144.html. ↩
3. FinfraG, Art. 125 paras. 3–4, https://www.droit-bilingue.ch/de-fr/9/95/958.1-125-134.html. ↩
4. Board Agenda, “Swiss court backs sale of Sika stake to Saint-Gobain”, 8 September 2015, https://boardagenda.com/2015/09/08/swiss-court-backs-sale-of-sika-stake-to-saint-gobain/. ↩
5. swissinfo.ch, “Court blocks Sika family from selling shares”, 30 October 2016, https://www.swissinfo.ch/eng/business/landmark-decision_court-rules-against-sika-family-owners-in-takeover-feud/42553734. The report notes that the agreed price represented a premium of about 80 per cent, reflecting the value of the voting control. ↩
6. Walder Wyss, “Sika Takeover: Settlement among the Burkard family, Compagnie de Saint-Gobain and Sika”, 13 May 2018, https://www.walderwyss.com/en/news/2018-05-13_uebernahme-von-sika-einigung-zwischen-der-familie-burkard-saint-gobain-und-sika. Under the settlement of 11 May 2018 Saint-Gobain acquired Schenker-Winkler Holding, which retained 10.75 per cent of Sika, while Sika undertook to introduce a single class of shares and to abolish the opting-out clause. ↩
7. FinfraG, Art. 135 para. 2, https://www.droit-bilingue.ch/de-fr/9/95/958.1-135-144.html. ↩
8. CMS, “CMS Expert Guide to Public Takeovers: Switzerland”, 18 September 2023, https://cms.law/en/int/expert-guides/cms-expert-guide-to-public-takeovers/switzerland. The guide also describes the standard timetable, with a cooling-off period of ten trading days, an offer period of twenty to forty trading days and an additional acceptance period of ten trading days, as well as the squeeze-out thresholds. ↩
9. Alexander Vogel, Christoph Heiz, Andrea Sieber and Debora Durrer (Meyerlustenberger Lachenal), “The end of Swiss control premiums”, IFLR, 1 March 2013, https://www.iflr.com/article/2a63733ixysbvckz96k3p/the-end-of-swiss-control-premiums. The earlier rule permitting a price up to 25 per cent below the highest price paid is described in the standard literature on Swiss takeover law. ↩
10. Swiss Takeover Board, home page, https://www.takeover.ch/. ↩
11. FINMA, “Public takeover bids”, https://www.finma.ch/en/enforcement/market-supervision/public-takeover-bids/. FINMA describes the TOB as reviewing mandatory and voluntary bids for compliance with the law. ↩
12. Daniel Raun, Andreas Hinsen and Rashid Bahar (Advestra), “Corporate M&A 2026: Switzerland – Trends and Developments”, Chambers Global Practice Guides, https://practiceguides.chambers.com/practice-guides/corporate-ma-2026/switzerland/trends-and-developments. The authors report that only two public tender offers were announced in 2025, for Zwahlen et Mayr and u-blox Holding, and that several large transactions with Swiss involvement took other forms, such as the spin-off of Amrize by Holcim and the statutory merger of Helvetia and Baloise. ↩

For general information only. This article does not constitute legal or tax advice, does not replace advice on an individual case and creates no lawyer-client relationship. It reflects the legal position as of September 2025.