Antitrust Basics for Competitors Planning a Collaboration

Two competitors can lawfully run a joint research program, share a factory, buy supplies together, or set an industry standard. What they cannot do — ever, under any business justification — is agree on the prices they charge, divide up customers or territories, or coordinate bids. The first category is judged on its effects; the second is treated as unlawful in itself. This is federal law, built on the Sherman Act and the FTC Act, and most states have their own antitrust statutes enforced by state attorneys general on top of it.

The agreements that have no defense

Section 1 of the Sherman Act, at 15 U.S.C. § 1, prohibits agreements in restraint of trade. Courts have long held that a small set of agreements between competitors are so likely to harm competition that no inquiry into their effects is needed. They are unlawful per se.

• Price fixing. Any agreement that affects price — a floor, a ceiling, a discount schedule, a surcharge, credit terms, or a coordinated increase.
• Bid rigging. Agreeing who will win, who will submit a losing cover bid, or who will sit a round out. This is a routine subject of federal criminal prosecution in public procurement.
• Market allocation. Dividing customers, territories, or product lines so that competitors stop competing for each other's business.
• Wage fixing and naked no-poach agreements. The agencies treat agreements between employers not to compete for workers, or to fix pay, as belonging in the same category.

"Agreement" is broader than a contract. A nod at a trade association dinner counts if a jury believes it happened. Prosecutors and plaintiffs prove agreements from circumstances — parallel pricing plus a meeting plus an opportunity — far more often than from a signed document.

Watch out: Criminal exposure here is personal, not just corporate. The Antitrust Division prosecutes individuals, and a company's indemnity does not remove that. Separately, private plaintiffs can recover treble damages and attorney's fees under the federal antitrust laws, which is why a single per se violation can generate class litigation for years.

Where the rule of reason applies

Everything that is not per se unlawful is analyzed under the rule of reason. The court asks whether the agreement harms competition in a defined market, whether it produces genuine procompetitive benefits, and whether those benefits could be achieved in a less restrictive way.

Two ideas do most of the work in practice. Integration: the more the parties genuinely combine assets, risk and capability, the more the arrangement looks like a joint enterprise rather than a cartel. Ancillarity: a restraint that is reasonably necessary to make a legitimate collaboration work — a limited exclusivity, a field-of-use restriction, a confidentiality obligation — is judged with the venture, while a restraint bolted on for its own sake is judged alone and may be per se unlawful even inside a real venture.

Market share matters too. The same exclusive supply arrangement is unremarkable between two small firms and serious between two firms that together hold most of a market. Our guide to joint venture agreements covers how to build the integration that this analysis rewards.

What the agencies' guidance does and does not do

The Federal Trade Commission and the Antitrust Division publish guidance describing how they approach competitor collaborations, including "safety zones" — combinations of market share and structure they say they will not normally challenge. That guidance is genuinely useful, and it is also not law. It binds neither a court nor a private plaintiff nor a state attorney general, and the agencies can and do revise it.

That last point matters as of mid-2026. The agencies rewrote their merger guidance in recent years and withdrew several older policy statements, including material that had supplied widely relied-on safe harbours for information exchange in some industries. Anyone working from a memo drafted years ago should confirm the underlying guidance still stands, starting from the FTC's competition guidance and the Antitrust Division's own pages.

Information exchange: the everyday risk

Most companies never plan a cartel. They attend an industry meeting, benchmark salaries, or ask a supplier what a rival is paying — and create an evidentiary record that looks like coordination. Section 5 of the FTC Act, at 15 U.S.C. § 45, also reaches unfair methods of competition that fall short of a Sherman Act agreement, which widens the exposure.

The features that make an exchange safer are well established: data that is historical rather than current or forward-looking, aggregated across enough participants that no company's figures can be reverse-engineered, collected and published by an independent third party, and available to buyers as well as sellers. The features that make it dangerous are the mirror image — current prices, individual company data, future intentions, and a small number of participants.

1. Set the agenda in writing. Circulate it before any competitor meeting and keep to it. Minutes that show what was discussed are a defense; their absence is not.
2. Name a stopping rule. Everyone attending should know to end the conversation and note the objection if pricing, capacity or wages come up.
3. Use a clean team. Where diligence or a venture requires competitor data, route it to people with no pricing responsibility.
4. Aggregate through a third party. Benchmarking through an independent administrator with anonymised, historical inputs is the standard structure.
5. Keep the record. Documents written casually about competitors are read later by people looking for intent.

The hiring side of the same rule

Agreements between employers not to solicit or hire each other's staff, and agreements about pay, are analyzed as agreements between competitors in a labor market. The Antitrust Division has pursued these criminally, and results at trial have been mixed, so the boundaries remain contested as of mid-2026. Restraints genuinely ancillary to a lawful transaction — a narrow non-solicit inside a real joint venture or acquisition — are treated differently from a naked agreement between rivals.

Where this bites in ordinary business

Public procurement is the sharpest example: bid rigging is prosecuted as a federal crime and can also carry suspension and debarment consequences for the companies involved. Firms bidding for government work should read our guide to federal registration and set-asides alongside this one, since teaming on a bid and coordinating a bid can look similar from the outside and are treated very differently.

Distribution raises its own questions. Agreements with resellers and agents are usually vertical rather than horizontal, and vertical restraints — including resale price maintenance — are generally analyzed under the rule of reason as a matter of federal law, though some states take a stricter view of resale price maintenance under their own statutes. Our explainer on independent sales representatives covers the contract side of those relationships, and franchise systems face a parallel set of issues discussed in our piece on franchise disclosure documents.

Common questions

We are small. Does antitrust law really apply to us?

Yes. The per se prohibitions have no size threshold — a price-fixing agreement between two small firms is unlawful on the same terms as one between two large ones. Size affects the rule-of-reason analysis, where market power is part of the question, and it affects whether an agency opens an investigation. It does not create an exemption, and private plaintiffs do not need the government to act first.

Can we talk to a competitor about buying supplies together?

Joint purchasing is one of the more commonly accepted collaborations, because it can produce real efficiencies. The risks are still specific: the group should not become a vehicle for sharing what members charge downstream, should not account for so much of the input market that suppliers have no alternative, and should let members buy outside the group. Structure and share drive the answer, not the label on the agreement.

Does a signed antitrust compliance policy protect the company?

A real program helps, and the Antitrust Division has said it considers the quality of a compliance program in charging and sentencing decisions. A policy nobody trains on or enforces helps very little. What counts is documented training, a reporting channel people actually use, controls around competitor contact, and evidence that the company acted when something surfaced.

What should someone do if a competitor raises price in a meeting?

Stop the discussion, say clearly that the topic is off limits, leave if it continues, and make a contemporaneous written record of the objection and the departure. Silence is the problem: courts and juries treat presence without objection as consistent with agreement. Reporting the incident internally the same day, in writing, is what turns a bad moment into a defense rather than an exhibit.

Working through a proposed collaboration

Write down what the collaboration actually does before deciding whether it is lawful. Most bad advice comes from analyzing a label — "joint venture", "alliance", "consortium" — instead of the conduct.

Then separate the pieces. Identify anything that touches price, output, customers, territories, bids or wages, and treat those as red lines rather than negotiating points. Test every remaining restraint against the venture's legitimate purpose: is it needed to make this work, and is it no broader than necessary in scope, duration and geography?

Put information controls in place before diligence begins, not after data has moved. Keep the analysis in a document you would be comfortable producing later. And check the agencies' current guidance rather than a stored copy — the FTC's business guidance library collects the material aimed at companies, and it changes.