Web services QoS management frameworks proposed in the literature deal essentially with issues such as QoS specification, QoS-based discovery and selection, and QoS monitoring of Web services. However, only few works have considered the issue of load distribution in a Web services context. In this paper, we investigate three models that might be used to achieve load distribution in a Web services environment. We focus on load distribution at the operation level by considering the assignment of methods execution to appropriate Web services according to some selection policies. The experiments we have conducted using the broker-oriented model have shown that better results are obtained using the random policy for Web service selection.