In this work we present a bilevel optimization method for simultaneous synthesis of heat exchanger networks (HENS). The results show that compared to a similar method using the same superstructure the presented method can provide comparative solutions to HENS problems with reduced calculation effort especially for larger problems. Hence the value of this work is a good way of simplifying a HENS problem so that HENS problems can be solved efficiently with good results. The presented method combines four submodels into an overall method by using grouping of streams, aggregate streams and bilevel optimization. The idea of the method is to decompose the set of binary variables i.e. the variables that define the existence of heat exchanger matches, into two separate problems. Three different HENS examples from the literature are solved. (C) 2010 Elsevier Ltd. All rights reserved.