Mercedes-Benz will unveil the new version of its largest SUV, the GLS, at next week's New York motor show, and prototypes have now been seen with minimal camouflage.

UPDATED: New Mercedes-Benz GLS: re-engineered luxury SUV unveiled

According to US media reports, the model will be shown two days after the unveiling of the GLB, which is destined for the Shanghai show.

The second-generation GLS sits on Mercedes' latest Modular High Architecture (MHA) platform, shared with the smaller GLE, giving it a similar footprint to the new BMW X7. This provides a significant reduction in kerb weight over the old GLS, the capability to support a 48V electrical architecture and the very latest in radar, camera and sensor-supported driving functions.

Like the outgoing GLS, the new model will share many parts with the S-Class luxury saloon, including its powertrains. The S-Class has six-cylinder and eight-cylinder turbo petrol engines, a six-cylinder diesel and a petrol-electric plug-in hybrid, so expect a similar line-up for the GLS.

An electrified powertrain will help to ensure the GLS can compete in regions with strict emissions limits and survive into the era of new European Union CO2 limit enforcement, which will begin in 2020.

At the top of the range will be a Mercedes-AMG GLS 63 featuring a twin-turbocharged 4.0-litre petrol V8, likely with the same 612bhp output as it has in the S63.

Mercedes-Maybach GLS on the cards for 2020

Mercedes is also planning to expand its luxury Maybach line with a plush range-topping version of the GLS next year.

The Mercedes-Maybach GLS will be marked out by unique vertical grille slats, chrome exterior detailing, unique wheels and distinct badging. The biggest changes will be to the interior, however, where Maybach is likely to ditch a seven-seat layout for five or six captain's chairs.