The Mercedes-AMG GT concept has been previewed with a sketch before it's revealed at the Geneva motor show next week.

Arriving in what is AMG's 50th year, the 600bhp-plus four-door saloon concept will provide clear hints to a production version that's due on roads in 2019.

New Mercedes-AMG GT Concept to make production in 2019

Designed with a coupé-like roofline and four door body, the GT concept sports a large rear diffuser that hints at hardcore performance capabilities for the future production car. It will use a twin-turbocharged 4.0-litre V8 engine, and will replace the CLS Shooting Brake in Mercedes' line-up.

As AMG's third dedicated series production model line, the GT four-door will follow on from the SLS and the existing GT, and arrive after AMG’s recently announced limited-volume, F1-inspired hypercar.

Mercedes-AMG GT 4-door revealed

Targeted at the the Porsche Panamera, BMW 6 Series Gran Coupé and Audi A7/RS7, the new saloon, codenamed X290, is the brainchild of AMG boss Tobias Moers.

Original plans for a model in the mould of the GT four-door were first aired in a series of patent applications filed by AMG in 2012. At the time, plans centred around a long-wheelbase version of the SLS featuring two gullwing doors and a pair of small, rear-hinged rear doors.

More recent plans for the performance saloon subsequently became more closely linked to the GT. But while the latest addition to AMG’s line-up will share key styling cues and elements of its mechanical package with the company’s headlining sports car, sources say it will be based on a different platform from the bespoke aluminium structure used by the GT.

The basis for the GT four-door is parent company Mercedes-Benz’s modular rear architecture (MRA), as used on the C 63, E 63 and S 63. It has been specially modified for the four-door GT, with what AMG insiders describe as 'unique' wheelbase and track width measurements.

We've driven the GT63 - take a look at our full review

Other dedicated features include the greater use of lightweight materials within the floorpan and body structure, most notably aluminium and hot-formed high-strength steel, the adoption of which is aimed at lowering the weight of the new model to below that of Mercedes-AMG’s existing MRA-based models in the search of greater performance potential and enhanced handling characteristics.

Power for the 2019 model will come from the latest evolution of AMG’s twin-turbocharged 4.0-litre V8, already confirmed for the new E 63. Among its developments is the adoption of new twin-scroll turbochargers mounted between the cylinder banks. These new units are claimed to provide improved induction qualities over the more conventional ones used in the existing version of the M177-designated engine.