In this paper we describe an activity of information integration performed on databases with patent data and company indicators. In particular, we present a detailed case study on company name matching. We show how to choose and tune existing methods to work on the domain object of this paper, and describe an efficient implementation to process large volumes of data. The integration activity involves the application of approximate string matching techniques. Then, we show the experimental results obtained on real data sets, highlighting the pros and cons of approximate string matching in this specific domain, and analyze the impact of domain knowledge on the results of the matching activity.