It is Ib Kofod Larsen for Brande. Model 57J.
See here (the BM is Brande Møbelindstri, which can be easily verified from marked specimens on the internet):
http://movablemodern.com/documents/617/document-excellent-furniture-comp...
and here (the design credit to Kofod Larsen):
http://movablemodern.com/documents/901/document-%C3%B8nskebo-catalog/pub...
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