The present invention pertains to a venetian blind (50) comprising an operating system and a plurality of horizontally disposed slats (55) suspended vertically from said operating system. In order to be suitable for use with large window panels (20) of modern high-rise building construction, the slats (55) are particularly large and stable. Each of the slats comprise an elongated hollow body made from aluminium sheet material and filled with foamed plastic material. The operating system allows flexible positioning of the support cords (60) and the stable slats (55) allow a large span between the supporting cords (60) without sagging of the slats (55).
