Oak Hill Capital consortium, a group of the U.S.-based private-equity firms, including Oak Hill Capital Partners, GenNx360 and Knox Lawrence International, has bought Vertex Data Science (Vertex), a business process outsourcing subsidiary of United Utilities for $427.23 million. The sale of the subsidiary is expected by the end of March 2007.

Under United Utilities’ ownership, Vertex has moved from an in-house service provider to establish itself as one of the leading business process outsourcing companies in the U.K. The sale to the Oak Hill Capital consortium represents a natural evolution to the next stage of its development under specialized ownership.