The car will be badged GT in recognition of the Opel GT subcompact coupe built between 1968 and 1973. The Geneva concept is expected to be a similar size.
Opel said in a statement that the GT concept will be a "breathtaking and puristic sportscar" that expresses the continuous innovative strength and the new lifestyle of Opel.
The design language will be an evolution of the "sculptural artistry meets German precision" look first seen on the Opel Insignia midsize car launched in 2008 and updated for the Monza coupe concept unveiled at the 2013 Frankfurt auto show, a spokesman said.
Buick, which sells vehicles based on Opel models, unveiled the Avista coupe concept this month at the Detroit auto show. The Opel GT is expected to be smaller than the Avista, which is based on a rear-wheel-drive platform and is powered by a twin-turbo V-6 gasoline engine.
German press reports said the GT concept may go into production based on the new Astra at the end of 2017 or early 2018 as an image booster for Opel.
