AAR Corp. has agreed to buy a 65% stake in an aircraft-maintenance firm backed by Bain Capital for $1.8 billion, the Wall Street Journal reports, in one of the largest transactions in the independent MRO sector in recent years.

The deal values the target company at an implied enterprise level of roughly $2.8 billion if the stake price reflects the whole business proportionally. The WSJ did not immediately publish full terms beyond the headline figure and the ownership split.

The acquisition, if completed, would materially expand AAR's airframe maintenance capacity at a moment when airline demand for third-party heavy checks and interior retrofits continues to outstrip available bay space across North America and Europe. Bain Capital, which backs the target firm, would retain a minority position under the structure reported.

AAR, listed on the New York Stock Exchange under the ticker AIR, has built its business around Parts Supply, Repair & Engineering, Integrated Solutions, and Expeditionary Services segments. Airframe maintenance has been a growth driver for the company in recent quarters, supported by aircraft staying in service longer as Boeing and Airbus delivery shortfalls push operators to extend the lives of current-generation narrowbodies and widebodies.

That dynamic cuts both ways for MRO providers. Older fleets generate more maintenance events per aircraft — more heavy checks, more component repairs, more structural work — but the sector has struggled to add capacity quickly. Skilled technician labor remains the binding constraint, and new hangay bays take years to permit and build. Consolidation is one of the few levers available to scale quickly.

The reported price underscores how private equity views the maintenance segment: steady, contracted, cash-generative work tied to fleets that must fly regardless of new-delivery timing. Bain's involvement on the sell side reflects that thesis. For AAR, paying $1.8 billion for a controlling 65% position signals confidence that maintenance demand will remain elevated through the decade as Airbus and Boeing work down backlogs that still exceed 13,000 aircraft combined.

The transaction, as reported, leaves open the question of governance and exit terms for the remaining 35%. Standard structures in such deals include put and call arrangements that would allow AAR to acquire the remainder over time, though the Journal's report did not specify these details.

Regulatory review will likely be straightforward given the fragmented nature of the independent MRO market, where AAR competes against ST Engineering, Lufthansa Technik, Delta TechOps, HAECO and a long tail of regional players. No single firm holds dominant share in North American airframe maintenance.

For airlines and lessors, the deal's practical consequence is capacity and pricing. A larger, better-capitalized AAR could accelerate bay expansions and workforce hiring at the acquired facilities, potentially easing turnaround times that have stretched at many independent shops. Alternatively, consolidated owners may prioritize margin over volume, keeping utilisation high and queues long.

The WSJ report did not name the target company's management or specify which sites would change operational control. AAR has not yet publicly confirmed the transaction, and the company typically discloses deal terms through press releases and Securities and Exchange Commission filings once agreements are signed.

Investors will watch AAR's next earnings call for financing details — whether the company funds the purchase with cash, debt or a mix, and how it plans to integrate the new capacity with its existing airframe network, which includes operations in Miami, Oklahoma City, Rockford and Grand Rapids.

Completion of the deal, subject to the confirmations and approvals ahead, would rank among the defining consolidation moves in the aftermarket this decade and position AAR to capture a larger share of maintenance spending that analysts project will grow steadily as the global fleet ages.