"It feels like a younger brother of a mix of the GLS and the G," Källenius said. "It has a little ruggedness of the G, it has some of the elegance of the GLS."
The production version will be unveiled this summer and available for sale in the U.S. in the fourth quarter. The GLB will be priced between a GLA and GLC, which would place its starting price in the mid-to-upper $30,000s.
An electric EQB version of the vehicle is scheduled for 2021.
In the U.S., the GLB will compete with the Lexus NX, Cadillac XT4 and BMW X1.
The GLB, referred to as the Baby G-Wagen, has an 111-inch wheelbase and fits up to seven people on a stretched A-class platform.
The concept is powered by a four-cylinder engine that delivers 224 hp. The engine's cylinder bore is widened at the lower end of the cylinder liners to minimize friction and thereby lower fuel consumption. The pistons feature cooling ducts for more efficient combustion. The aluminum four-valve cylinder head features a variable-valve timing system that can increase fuel efficiency or boost the engine's performance.
The vehicle also features all-wheel drive and an eight-speed dual-clutch transmission.
The GLB is "the combination of our SUV genes... [with the] clear lines of our compact vehicles," Mathias Geisen, director of product manager, told Automotive News.
That will make the GLB especially attractive to U.S. buyers, he predicted.
"The capability of handling seven people in a compact footprint in larger cities will be highly appreciated," Geisen said.
The GLB will give Mercedes showrooms another crossover aimed at entry-level luxury customers.
Overall, sales of luxury compact crossovers rose 13 percent in the first quarter, making it one of the fastest-growing product segments.