There are many clustering methods available and each of them may give a different grouping of datasets. It is proven that hybrid clustering algorithms give efficient results over the other algorithms. In this paper, we propose an efficient hybrid clustering algorithm by combining the features of leader's method which is an incremental clustering method and complete linkage algorithm which is a hierarchical clustering procedure. It is most common to find the dissimilarity between two clusters as the distance between their centorids or the distance between two closest (or farthest) data points. However, these measures may not give efficient clustering results in all cases. So, we propose a new similarity measure, known as cohesion to find the intercluster distance. By using this measure of cohesion, a two level clustering algorithm is proposed, which runs in linear time to the size of input data set. We demonstrate the effectiveness of the clustering procedure by using the leader's algorithm and cohesion similarity measure. The proposed method works in two steps: In the first step, the features of incremental and hierarchical clustering methods are combined to partition the input data set into several smaller subclusters. In the second step, subclusters are merged continuously based on cohesion similarity measure. We demonstrate the effectiveness of this framework for the web mining applications. © 2010 IEEE.