Mercedes-Benz will launch a roadster version of its SLR McLaren, complete with retractable roof, in September.

The roof opens and closes in less than 10 seconds but needs to be unlocked from the windscreen frame, after which it folds away electrically.

The roadster version is powered by the same AMG V8 compressor engine as the coupe version, which delivers 626bhp and a top speed of 207mph.

Standard equipment includes semi-aniline-leather-upholstered carbon-fibre bucket seats; dual-zone automatic air-conditioning; BOSE sound system; multifunction sport steering wheel with gear-change paddles and a navigation system with integral radio and CD player.

The new SLR McLaren roadster goes on sale in September. Prices will be announced nearer to launch.

Mercedes says conversation with the top down is still possible at speeds of 124mph thanks to specially developed aero acoustics.