This post is in partnership with Fortune, which offers the latest business and finance news. Read the article below originally published at Fortune.com. By Doron Levin General Motors’ Cadillac brand is setting up a headquarters office in New York in order to be closer to other premium jewelry, design and high fashion businesses and the consumers who buy their brands. The relocation is the first major initiative to shake up and energize Cadillac’s sluggish business by Johan de Nysschen, who took over as the brand’s boss in August, following stints at premium automotive brands Infiniti and, before that, Audi.