Private equity firms Wafra Partners and Landmark Partners acquired a minority stake in Siris Capital Group, a leading private equity firm focused on investing and driving value creation in mature technology companies. Financial terms were not disclosed. Russell Valdez, Chief Investment Officer of Wafra, said: "Driven by a talented investing team with deep domain expertise, Siris has the right infrastructure in place to skillfully execute on its differentiated investment strategy. Together with our partners, we look forward to the firm's continued success."