AAR has agreed to buy a majority stake in MRO Holdings, an aircraft maintenance provider, in a transaction valued at $1.8 billion, Reuters reports.

The deal ranks among the most significant consolidations in the independent aircraft maintenance, repair and overhaul sector in recent years. For AAR, an Illinois-based aftermarket services and supply chain company, the acquisition of MRO Holdings expands its airframe maintenance footprint at a moment when airline demand for third-party MRO capacity continues to outstrip supply.

MRO Holdings operates airframe heavy maintenance operations that serve commercial airline customers across the Americas. The company has positioned itself as a consolidator of maintenance facilities, an approach that AAR is now effectively extending by purchasing a controlling position in the business.

The $1.8 billion valuation signals how much strategic weight the aftermarket now carries across the aviation value chain. Aircraft on ground time, engine shop visits and heavy airframe checks have become bottleneck points for operators worldwide as fleets age and new deliveries arrive more slowly than airlines planned. Maintenance capacity, rather than aircraft orders, has increasingly become the constraint on network reliability.

For AAR, the transaction follows a period in which the company has built out its portfolio across parts distribution, government services and airframe maintenance. Acquiring a controlling stake in MRO Holdings gives AAR access to additional maintenance lines and skilled labor capacity, the two inputs that airlines and lessors now compete for most aggressively.

A majority stake structure, rather than a full buyout, leaves existing MRO Holdings investors with exposure to the combined business. Reuters did not report the exact percentage AAR will hold, the expected closing date, or the financing structure of the transaction in the initial disclosure.

Consolidation among independent MRO providers has accelerated as OEMs push deeper into the aftermarket with their own service programs. Scale increasingly determines whether an independent provider can win long-term component and airframe support contracts from major carriers and lessors. A deal of this size positions AAR more directly against both larger independent rivals and OEM captive shops.

The transaction remains subject to customary closing conditions and regulatory review, standard steps for an acquisition of this magnitude in the aviation services sector. AAR and MRO Holdings will provide further detail on the structure, financing and integration timeline as the deal progresses toward completion.