Reliance Steel & Aluminum, a metals service center operator, completed the acquisition of Merfish United, a distributor of carbon steel pipes, fittings and flanges, from One Equity Partners, a middle market private equity firm. Financial terms were not disclosed. "We identified Merfish as a unique business with strong growth prospects led by a talented management team. We're proud of our work with Merfish United's CEO Greg Leidner, Chairman Gerald Merfish and their team over the past eight years to create one of the largest master distributors of competitively priced standard pipe and tube products in North America," Jamie Koven, OEP Senior Managing Director.