The spatial clustering of interconnected firms is a frequently observed phenomenon; this is also the case in Amsterdam. Clusters are believed to contribute to the economic growth of a region. The increased economic growth, results from improved enterprise competitiveness related with positive external economies, such as a common skilled labour pool, the availability of specialized suppliers, a critical mass of clients and knowledge transfers. The focus of this paper is on clusters of sectors with a high share in office employment. It is plausible; that clusters of specific sectors will be located at urban locations where the location features match with sector specific requirements. These urban areas of sectoral specialization could also be an indication of the spatial office submarket structure. Analyses of local office space markets often assume a unitary market, which implies that the prices of office features remains constant across the entire market. However, different sectors have widely varying preferences and their willingness to pay for those features may also vary. As a matter of fact, the stratified structure of the office market is often mentioned and the office market is frequently described as a set of interrelated submarkets. Based upon the analyzed pattern of spatial sectoral concentration, clusters, office submarkets are determined. Subsequently, a study is undertaken to test if the determined submarkets accurately represent the office market segments. The results of this paper, provides insight into the location preferences of the various sectors and into the office submarket structure.