Merger Control in Argentina: From (the Impossibility of) Unscrambling the Eggs to Ex-Ante Review (1999-2026)

This paper examines the evolution of Argentina's merger control regime from its establishment under Law No. 25,156 in 1999 through the transformative reform introduced by the Competition Defense Law No. 27,442 in 2018, and up to the forthcoming entry into force of a fully ex-ante notification and review system scheduled for November 2026. The analysis traces the institutional, procedural, and substantive dimensions of this trajectory, evaluates the structural weaknesses of the post-notification model, and assesses the significance of the transition to a suspensory pre-merger review system aligned with international best practices.

Introduction

Merger control—the legal mechanism by which competition authorities assess whether corporate concentrations are likely to harm market competition—stands as one of the cornerstones of modern antitrust law. Its institutional design choices carry profound implications for market structure, investment certainty, and the credibility of competition enforcement.

Argentina's experience in this domain offers a uniquely instructive case study: a country that adopted a merger notification regime in 1999, lived with its structural deficiencies for nearly three decades, undertook a comprehensive legislative overhaul in 2018, and is now—after an unusually prolonged transitional period—on the verge of implementing a genuinely effective ex-ante review system.

The journey from the enactment of Law No. 25,156 to the full operationalization of Law No. 27,442 encompasses not merely a change in legal text, but a transformation in institutional architecture, enforcement philosophy, and Argentina's positioning within the global landscape of competition policy. Understanding this trajectory is essential both for practitioners operating in Argentine markets and for scholars of comparative competition law.

The 1999 Regime: Post-Notification and Its Structural Deficiencies

Argentina's first comprehensive merger control framework was established by Law No. 25,156 of 1999. The statute introduced mandatory notification thresholds and created the Tribunal Nacional de Defensa de la Competencia (TNDC).

The TNDC was never established, and the Comisión Nacional de Defensa de la Competencia (CNDC) continued to act as the primary reviewing body, while final decision-making rested with the political sphere via the Secretariat of Commerce. On its face, the law appeared to adopt international standards; in practice, however, its design contained a fundamental flaw that would define—and undermine—Argentine merger control for the following nineteen years. This approach triggered extreme regulatory backlogs, with cases taking years to resolve, causing severe legal uncertainty for integrated firms.

The 1999 regime was structured as a post-closing notification system. Although pre-merger notification was not prohibited, parties were permitted—indeed, required—to notify transactions after their consummation. This meant that by the time the CNDC conducted its substantive review, the merger had already been completed: assets transferred, operations integrated, and organizational structures merged. The authority could, in theory, order divestiture or impose conditions; in practice, the costs and complexities of unwinding consummated transactions created powerful deterrents against robust enforcement. The system thus suffered from a structural bias toward permissiveness.

Compounding this design defect were chronic institutional weaknesses. The CNDC operated with insufficient resources, limited technical capacity relative to the volume of notifications, and an absence of binding statutory deadlines that created endemic delays. Cases often languished for years without resolution. The authority's recommendations, moreover, were subject to political override by the Secretariat of Commerce, which introduced an additional layer of uncertainty and rendered enforcement outcomes difficult to predict. Foreign investors and domestic conglomerates alike navigated a regime that was nominally rigorous but substantively porous.

The aggregate effect was a merger control system that offered the appearance of oversight without its substance. Large-scale concentrations in key sectors—telecommunications, energy, agribusiness, retail—proceeded largely unimpeded. The credibility of Argentine competition enforcement suffered correspondingly, both domestically and in the eyes of multilateral bodies and foreign counterparts.

Law No. 27,442 of 2018: A Legislative Overhaul

The enactment of Law No. 27,442 in May 2018 represented a genuine paradigm shift in Argentine competition policy. The reform was comprehensive in scope, addressing substantive provisions, procedural architecture, and—most significantly for merger control—the fundamental notification model. The new law embraced, at least in its design, the ex-ante review standard that characterizes best-practice merger control in jurisdictions such as the European Union, the United States, and Brazil. However, Section 84 of Law No. 27,442 stipulated that the ex-ante mechanism would only activate one year after the Autoridad Nacional de la Competencia (ANC) was officially constituted.

Under Law No. 27,442, concentrations meeting specified thresholds would be required to notify and obtain clearance before closing. The suspensory effect of notification—colloquially, the "standstill obligation"—is the essential feature that distinguishes a genuine ex-ante system from its post-consummation counterpart. By prohibiting closing prior to clearance, the law eliminates the structural disincentive against remedy imposition that plagued the 1999 regime1. Authorities reviewing a pre-merger notification are not confronted with the politically and economically fraught task of dismantling an already-integrated enterprise; they operate, instead, from a position of genuine leverage.

Law No. 27,442 also introduced institutional reforms of considerable importance. It established the ANC as a new, technically specialized, and—critically—more independent authority, replacing the fragmented institutional structure under which the CNDC made recommendations that the Secretariat of Commerce could freely disregard. The ANC was conceived as a collegial body with autonomous status, insulated from day-to-day political influence.

The law further introduced binding review periods, clearer substantive standards, a leniency regime for cartel matters, and a comprehensive private enforcement system, constituting a holistic modernization of Argentine competition law.

The Transitional Period: 2018–2026

Deferred Implementation of Ex-ante Review

Despite the legislative ambition of Law No. 27,442, its merger control provisions—specifically the ex-ante, suspensory notification regime—did not enter into force immediately upon enactment. The law established a transitional arrangement whereby the post-notification system of Law No. 25,156 would continue to apply until the new institutional infrastructure was operational. This deferred implementation reflected both the complexity of establishing the ANC from scratch and, arguably, the political sensitivity of imposing filing fees and mandatory pre-closing review on a business community accustomed to the more permissive prior regime.

The transitional period proved far longer than originally anticipated. Administrative challenges to the ANC's formal constitution, successive changes in government with varying levels of commitment to competition policy reform, and the economic disruptions associated with the COVID-19 pandemic collectively conspired to delay full implementation. For nearly eight years following the law's enactment, Argentina continued to operate, in substance, under a modified version of the post-notification model—a paradox that drew criticism from competition academics and international observers alike.

The Formal Constitution of the ANC (2026)

The institutional deadlock finally started to break in November 2025. Through Decrees 803/2025 and 810/2025, the executive branch officially constituted the ANC and appointed its specialized authorities. This milestone activated the statutory one-year countdown under Section 84 of Law No. 27,442. The Senate unanimously granted the agreement required by Section 23 of Law No. 27,442, in April, 2026.

A final definitive step was taken with Decree No. 284/2026, by which the executive branch formally constituted the ANC and initiated the process of transitioning to the ex-ante review system. The decree marked the end of the regulatory limbo that had characterized Argentine merger control since 2018 and set in motion the administrative preparations—including the publication of implementing regulations, the operationalization of the notification portal, and the staffing of specialized review teams—required for the new system to function effectively.

The formal constitution of the ANC also carried symbolic and signaling significance. It conveyed to market participants, foreign investors, and international organizations that the Argentine state was committed to implementing the structural competition law reforms contemplated in 2018. Against the backdrop of Argentina's ongoing engagement with the IMF and its broader economic stabilization program, demonstrating institutional seriousness in competition enforcement carries additional weight.

November 2026: The Entry Into Force of Suspensory Ex-ante Review

The ex-ante, suspensory merger control regime under Law No. 27,442 is scheduled to enter into full force on 17 November 20262.

From that date, transactions meeting the applicable turnover and market thresholds will be required to notify the ANC before closing and to observe the standstill obligation pending a clearance decision3. Consummating a deal prior to clearance will be strictly illegal, rendering transactions void and subject to severe financial penalties.

The ANC will be empowered to clear transactions unconditionally, to impose behavioral or structural remedies as conditions of clearance, or—in cases presenting serious competitive concerns—to prohibit the transaction entirely.

The shift to a suspensory regime fundamentally alters the engineering of M&A transactions in Argentina. Under the ex-ante framework, obtaining unconditional clearance from the ANC becomes a critical regulatory Condition Precedent (CP) in Share Purchase Agreements (SPAs), legally freezing the closing of the deal. Consequently, transaction parties are forced to negotiate significantly broader long-stop dates and structured break-up fees to allocate the financial risk of potential regulatory delays or prohibitions. Furthermore, to prepare the mandatory notification without running afoul of antitrust rules, competing undertakings must implement strict 'Clean Team' protocols to isolate and handle competitively sensitive information during the due diligence phase.

Recent Case Law Development: The Nature of Gun-Jumping Infractions and the Statute of Limitations (Trappa Case, 2026)

In a decision issued on May 8, 2026, the Federal Civil and Commercial Court of Appeals (Chamber II), in Trappa, Rolando Carlos y otros c. Estado Nacional4, clarified a fundamental and long-debated aspect of Argentine merger control: the legal nature of a failure to notify an economic concentration (i.e., gun-jumping) and how its statute of limitations must be calculated. The case arose after the CNDC sought to penalize individual buyers for an unnotified transaction originally closed in 2011, imposing heavy retroactive daily fines more than a decade later.

The Court’s ruling establishes several critical principles for M&A and antitrust practitioners, as well as for regulatory compliance in Argentina:

• Instantaneous Nature of the Infraction: The Court definitively ruled that the failure to notify an economic concentration within the statutory deadline is an instantaneous infraction, rather than a continuous or ongoing violation. Because the law mandates a specific act to be performed within a fixed timeframe, the infraction is fully consummated the exact moment that deadline expires.

• Infraction vs. Ongoing Consequences: Crucially, the tribunal distinguished the illegal conduct itself from its subsequent financial penalties. The Court clarified that while the daily fines accumulate over time, this mechanism represents the consequences of the violation rather than a prolongation of the illegal status or conduct.

• Strict Calculation of the Statute of Limitations: Operating under the principle that the infraction is instantaneous, the five-year statute of limitations (prescription) begins to run immediately on the day following the missed filing deadline. In Trappa, because the transaction closed in late 2011, the limitation period had fully expired by December 2016, rendering the administration's subsequent 2023 penalty entirely time-barred.

• Proper Targeting of Liability: The ruling also underscores that the legal obligation to notify an economic concentration rests strictly upon the acquiring parties, not the target companies. Consequently, administrative or investigative steps mistakenly directed by the CNDC toward the target companies do not interrupt or toll the statute of limitations regarding the actual individual buyers.

This precedent provides vital legal certainty for the M&A market, while Argentina enters the new era of pre-merger control. By firmly rejecting the concept of a "continuous infraction" for failure to file, the Court has placed a clear temporal boundary on the state's punitive powers, protecting transaction parties from indefinite exposure to retroactive penalties for historical, unnotified transactions.

Crucially, as Argentina transitions into this ex-ante era, the legal exposure to gun-jumping infractions will expand far beyond the mere omission highlighted in the Trappa case. Under a suspensory review system, gun-jumping encompasses not only a failure to file within a deadline, but also any form of premature integration before explicit clearance is granted. Parties will face severe liability if they engage in pre-clearance coordination, such as unifying price lists, integrating sales forces, or transferring operational control of the target company. Managing this interim period—maintaining strict operational independence while advancing towards a future merger—represents the new compliance frontier for Argentine M&A.

Substantive and Procedural Alignment with International Best Practices

Historically, Argentina’s long-standing post-closing regime was an international outlier that compromised effective antitrust enforcement. Reviewing mergers years after operational integration made structural remedies practically impossible and undermined market predictability, protecting entrenched interests rather than competition.

The shift to ex-ante review positions Argentina alongside the established merger control jurisdictions, marking a monumental institutional turning point. The European Union's Merger Regulation (Council Regulation (EC) No. 139/2004) and Brazil's Law No. 12,529/2011—arguably Argentina's most relevant comparator given geographic proximity and economic integration through MERCOSUR—both operate suspensory ex-ante regimes. So too do the United States (under the Hart-Scott-Rodino Act), Canada, Mexico, and the vast majority of OECD member states.

The substantive standard under Law No. 27,442 adopts a competitive effects test, focusing on whether a concentration would substantially lessen or impede competition in a relevant market. This standard aligns with the dominant global approach. The incorporation of efficiencies as a countervailing consideration—consistent with the SIEC (Significant Impediment to Effective Competition) test applied in the EU—is also a feature of the Argentine framework, enhancing its analytical sophistication.

Procedurally, the introduction of binding review clocks is a particularly significant improvement over the 1999 regime. Parties will be entitled to a decision within prescribed periods, creating the investment certainty that the prior system conspicuously lacked.

To mitigate the systemic risk of an institutional bottleneck, the implementation of a formalized 'Fast-Track' or simplified procedure is imperative5. Subjecting every notified concentration to an exhaustive, deep-dive review would inevitably paralyze transactional activity. Establishing an expedited review path—guaranteeing clearance within a brief, statutory window (e.g., not more than 15 business days) for non-problematic deals—is essential to preserve the country's investment fluidity while safeguarding its markets.

The ANC's anticipated publication of guidelines on notification requirements, market definition methodology, and substantive assessment criteria will further enhance transparency and predictability.

Conclusions: A Historical Assessment and Prospective Analysis

Historical Assessment

The history of Argentine merger control from 1999 to 2026 is, at one level, a history of institutional underperformance. A legal framework that purported to introduce rigorous merger oversight was neutralized by structural design flaws—most fundamentally, the post-closing notification model—and by chronic deficits of institutional capacity, independence, and political will. The net result was nearly three decades during which major market concentrations proceeded with minimal effective scrutiny, contributing to the entrenchment of market power in multiple sectors of the Argentine economy.

And yet the same history can be read as a story of gradual institutional learning and eventual reform. The enactment of Law No. 27,442 in 2018 demonstrated that Argentine legislators were capable of producing a technically sound and internationally benchmarked competition statute. The challenge was always one of implementation rather than design. The protracted transition period, frustrating as it has been, ultimately gave the country time to build the institutional infrastructure—the ANC's human capital, information systems, and procedural protocols—necessary to sustain an ex-ante regime in practice rather than merely on paper.

Prospective Analysis: What the Transition Means for Argentina

The entry into force of suspensory ex-ante merger review in November 2026 carries implications that extend well beyond the technical domain of competition enforcement. At the macroeconomic level, it represents Argentina's meaningful integration into the international community of serious competition jurisdictions—a signal of institutional maturity that is likely to be received favorably by foreign direct investors who routinely factor regulatory quality into market entry decisions.

For domestic market structure, the new regime offers the prospect of genuinely contestable markets in sectors where unchecked consolidation has historically generated consumer harm. Energy, financial services, telecommunications, agribusiness, health, and retail are among the industries where effective merger review will be most consequential. The ANC's capacity to impose structural remedies6—and, where necessary, to block transactions—will act as a deterrent against anti-competitive merger strategies that the prior regime was powerless to prevent.

The broader significance of this transition lies in its contribution to the normative infrastructure of a market economy. Competition law is not merely a technical regulatory field; it is a structural guarantee of economic pluralism, ensuring that market outcomes reflect competitive dynamics rather than the exercise of unchecked private power. Argentina's belated but genuine adoption of international best practices in merger control is, in this sense, an investment in the long-term quality of its market institutions—and, through them, in the welfare of Argentine consumers and the sustainability of economic growth.

The road ahead is not without challenges. The ANC will need to develop jurisprudence rapidly, recruit and retain technically qualified staff, and navigate the political pressures that invariably attend high-profile transactions. International cooperation with peer authorities—particularly Brazil's CADE, the European Commission, and the U.S. agencies—will be essential in cases involving cross-border concentrations. The publication of clear, well-reasoned, and publicly available merger decisions will be indispensable for building the institutional reputation on which the authority's long-term credibility depends.

If these challenges are met with the seriousness they demand, November 2026 may come to be seen not merely as a procedural milestone in Argentine competition law, but as a turning point in the country's relationship with the rule of law as applied to economic power—a relationship that, after a long and difficult history, may finally be entering its maturity.