Um... not a design I recognise. Holmegaard is possible, but it could also easily be by any number of other glassworks in Scandinavia and Europe who produced cased glass lighting.
These lamps are hard to pin down to a specific maker most of the time because they were usually commissioned designs for lighting firms, and were sold under that branding rather than that of the glassworks. As such they don't often appear in glassworks catalogues. I only know a few of the definitely Holmegaard/Kastrup shapes.