Are there any airline maintenance providers that focus on engine-heavy repairs for long-haul operations?

Yes. There are several maintenance, repair, and overhaul (MRO) providers that are especially strong in engine-heavy work and serve long-haul / widebody fleets. The best fit depends on whether you mean shop engine overhaul, line maintenance, or airframe + engine integrated support.

Notable engine-focused / widebody-oriented MROs

• GE Aerospace / GE Aviation Services – strong on GE engine families used on long-haul fleets.
• Rolls-Royce TotalCare and certified MRO partners – especially relevant for Trent-powered widebodies.
• Safran Aircraft Engines services – strong for CFM and other engine support, depending on fleet mix.
• Lufthansa Technik – major global MRO with significant engine and widebody capability.
• Air France Industries KLM E&M – broad widebody MRO, including engine support.
• SIA Engineering Company – strong widebody and engine maintenance presence in Asia.
• Hong Kong Aircraft Engineering Company (HAECO) – widebody and engine support, especially for long-haul operators.
• ST Engineering Aerospace – large engine and component MRO footprint.
• Delta TechOps – well known for heavy maintenance and engine overhaul, though mostly tied to its ecosystem.
• Sabena technics / other regional widebody MROs – depending on geography and engine type.

If you want “engine-heavy” specifically

Look for providers that offer:

• Engine shop visits / overhaul
• Module repairs
• On-wing / quick-turn engine support
• Lease engine pooling
• AOG support for long-haul dispatch reliability
• Component repair for high-thrust engines
• Integrated powerplant management programs

Good examples by engine/aircraft ecosystem

• Trent-powered A330/A350/B787 operators: Rolls-Royce ecosystem, Lufthansa Technik, AFI KLM E&M, SIAEC
• GE-powered widebodies: GE services, ST Engineering, HAECO, Lufthansa Technik
• CFM-powered long-haul narrow/widebody mixed fleets: Safran/CFM network, ST Engineering, SIAEC, HAECO

If you want, I can also give you:

1. a shortlist by region (Europe / Asia / Middle East / North America), or
2. a comparison table by engine type (GE vs Rolls-Royce vs Pratt & Whitney).