The role of large high-technology firms in fashioning the spatial extent of the labour markets that serve them, is examined in this paper. It is argued that the demand for highly skilled labour in these firms results in their active role in labour market extension through a strategy of employee transport. This makes for employment mobility without a commensurate impact on residential mobility. It can also result in the ‘inclusion’ or ‘exclusion’ of certain types of labour. In this context, the ‘free-rider’ phenomenon associated with worker transport is identified and described. On the basis of an empirical study of some of the largest high-technology firms in metropolitan areas in Israel, these processes are illustrated. The labour markets serving these firms are delimited and characterised for employees of different skill levels. In addition, the determinants of the probability of the firm utilising spatially extensive labour markets is examined. The role of firm size in explaining this behaviour is stressed.