Usually in the monocentric city models, the spatial patterns of segregated ethnic groups are assumed to be ring-shaped, while early in the 1930ies, Homer Hoyt showed, that wedge-shaped areas predominate empirically. After Rose-Ackerman's discussion of the influence of aversion one group of households has against living close to members of another group within a ring-shaped segregated pattern, Yinger showes that a wedge-shaped pattern could arise, depending on the population mix, as long as border length is responsible for the spatial pattern. In this contribution, a monocentric model with the assumption of different household groups, a specific production function for housing and other goods and a specific utility function of households is presented. At first, border length is founded as a criterion of optimality. Secondly, it is shown that mixed patterns of concentric and wedge-shaped areas represent multiple equilibria if more than two groups of households are being considered. The welfare optimal segregated pattern depends on the relative production coefficient of households of different groups in the production of goods. This, for example, allows to analyse the impact of actual global production conditions on the spatial patterns of segregation in cities.