Ocean carrier alliance news moves fast and explains little. It tells you Maersk and Hapag-Lloyd formed Gemini Cooperation, or that MSC struck a deal with the Premier Alliance carriers, without explaining what any of that actually means for a booking. The mechanism underneath the headlines is a vessel sharing agreement, and understanding it answers a question that matters every time something goes wrong: which carrier is actually responsible for your cargo.
Three things that are not the same
The US Federal Maritime Commission, which regulates this activity, defines three distinct arrangements, and the industry habitually blurs them:
- Vessel Sharing Agreement (VSA). Two or more carriers jointly deploy a pool of vessels on a route or string, and each carrier independently sells the resulting space under its own name. Nobody "owns" the joint service; each partner contributes tonnage and takes a corresponding share of the capacity.
- Space charter, or slot charter. One carrier simply buys space on another carrier's existing service, in exchange for payment or services. There is no joint deployment and no shared decision-making, just a transaction for capacity.
- Global Vessel Sharing Alliance. The FMC's own term for what the industry calls an alliance: functionally the same VSA mechanism, but spanning many trade lanes at once under one filed agreement. Gemini Cooperation, Premier Alliance and Ocean Alliance are each, legally, one filed Global VSA covering multiple strings, sometimes layered with separate slot deals to non-members.
A slot exchange is the reciprocal version of a slot charter: two carriers swap space on each other's services rather than one paying the other in cash. All three mechanisms can coexist on the same trade lane, which is exactly what happened when MSC arranged a slot exchange on nine Asia-Europe services with the Premier Alliance carriers without itself joining their VSA as a partner.
The legal machinery: how a VSA gets antitrust immunity
Ocean carrier cooperation of this kind would ordinarily raise serious antitrust questions, and it is permitted only because of a specific statutory framework.
In the United States, agreements among ocean common carriers must be filed with the FMC under the Shipping Act. Once filed, the FMC has seven days to publish a Federal Register notice inviting comment, and the agreement takes effect on the 45th day after filing or the 30th day after Federal Register publication, whichever is later, unless the FMC rejects it on preliminary review or goes to federal court to seek an injunction. Once an agreement has been filed and is effective, antitrust law does not apply to it: immunity attaches automatically, with no separate approval step, subject to a short list of carve-outs (certain domestic-carrier agreements, inland US through-rate discussions, joint terminal construction and loyalty contracts are excluded from the immunity).
The process runs to a real clock in practice. Gemini Cooperation, the Maersk and Hapag-Lloyd VSA, was filed 31 May 2024; the FMC issued a request for additional information on 12 July; the carriers responded 26 July; and the agreement took effect 9 September 2024, with the FMC stating it found no basis to seek an injunction, subject to ongoing monitoring. Premier Alliance, the HMM, ONE and Yang Ming agreement, followed a near-identical path: filed 28 October 2024, an information request 5 November, a satisfactory response by 26 December, and effect from 9 February 2025.
Europe just took the opposite path, and this is the fact worth getting right
For decades the EU ran a parallel system, the Consortia Block Exemption Regulation, which exempted liner shipping consortia from ordinary EU antitrust rules below a market-share threshold. It expired on 25 April 2024, and the European Commission decided not to renew it. There is no successor regulation specific to shipping. The Commission's own current position, stated on its live competition policy page, is that the general EU competition rules and the standard procedural regulation now apply fully to the maritime sector, with no shipping-specific exemption in place.
The Commission's stated reasoning was that the exemption had limited effectiveness, that only a small number of consortia actually relied on it, and that it no longer served its purpose of promoting competition in the sector. The practical consequence for carriers operating VSAs on European trades: cooperation must now be self-assessed against the general Treaty competition rules, using the Commission's ordinary horizontal cooperation guidelines rather than a shipping-specific safe harbour, and carriers are expected to keep that self-assessment on file. The Commission has said it will not issue shipping-specific guidance to replace what lapsed.
Treat any source describing the block exemption as still active, or citing an expiry date other than 25 April 2024, as out of date.
How slot allocation actually works
Inside a VSA, each partner's share of capacity tracks what it contributes, not an even split. Gemini Cooperation is the clearest current illustration: Maersk contributes 60% of the pooled network's capacity and Hapag-Lloyd 40%, across a fleet of roughly 340 vessels totalling about 3.7 million TEU, organised as a hub-and-spoke network of parallel mainline and shuttle services. Neither carrier owns the pool; each owns its contributed ships and takes a proportional share of the space the pool as a whole can sell.
A VSA also governs how the partners handle disruption. Filed agreement language typically gives the partners joint authority to agree temporary capacity adjustments, including blank sailings, with an accompanying compensation mechanism between them, and treats vessel substitution as something the substituting carrier bears the cost of, within operational parameters the partners set collectively. The point to take from this: a blank sailing or a vessel swap on a joint service is not one carrier's unilateral call, even though from the outside it can look that way.
Why carriers do this instead of running standalone services
No single carrier necessarily has enough ships to run a weekly service across every port pair a competitive network needs, and building that capacity alone is a large capital commitment against uncertain future demand. Pooling with a partner delivers broader port coverage and higher sailing frequency than either carrier's own fleet could sustain on its own, without either one owning more tonnage than it already does. Gemini Cooperation's stated aim of materially improving schedule reliability across a joint network neither partner was achieving independently is the clearest recent illustration of that logic in practice.
Which carrier is actually on the hook for your cargo
This is the part that matters when something goes wrong, and it is standard maritime contract law rather than anything the VSA filing itself changes. The carrier that issued your bill of lading, the one you actually booked with, is the contracting carrier, and its bill of lading terms, including its liability limits, govern your claim. It does not matter which VSA partner's vessel physically carried the container on that voyage. The partner that actually operated the sailing is typically shielded from a direct suit by a Himalaya clause in the contracting carrier's bill of lading, which extends the contracting carrier's own defences and limits to the actual performing carrier and other parties involved in the carriage.
The practical consequence: address a cargo claim to whoever issued your bill of lading and made your booking, not to whichever VSA partner happened to own the ship. Confusing the two is a common and avoidable mistake at the booking desk. Our guide to bill of lading types covers the document itself, and if a claim does arise, handling a cargo claim covers what happens next.
The alliance landscape today, briefly
The three current groupings are Gemini Cooperation (Maersk, Hapag-Lloyd), Premier Alliance (HMM, ONE, Yang Ming, joined by a separate MSC slot exchange on Asia-Europe lanes) and Ocean Alliance (CMA CGM, COSCO, OOCL, Evergreen). The prior structure, built around 2M (Maersk and MSC) and THE Alliance, ended in early 2025: Maersk and MSC wound down 2M in January 2025, after which MSC launched its own standalone network rather than joining a full VSA, entering only the narrower slot exchange with the Premier Alliance carriers described above. If you are reading content that still describes 2M or THE Alliance as active, or that treats "VSA," "slot charter" and "alliance" as interchangeable terms, it predates this realignment or is describing the mechanism loosely rather than precisely.
None of this changes the country gate or the mechanics of booking a shipment, but it does change which door a claim, a schedule query or a booking amendment should go through. Our guide to ocean freight transit times covers what a joint network actually delivers on the water, and how freight rates are calculated covers the commercial side of the same networks.
A forwarder who understands which alliance and which specific service your cargo is moving on is better placed to chase a delay or a claim to the right desk the first time. You can search more than 29,300 logistics companies by country and service in the CargoLinked directory, or post your shipment and let forwarders with ocean freight experience come to you.
