Thompson Street Capital Partners, a private equity firm, agreed to invest in Sageview-backed National Arbitration & Mediation, alternative dispute resolution services provider. Financial terms were not disclosed. "Our investment philosophy places a premium on partnering collaboratively with founders and management teams operating in defensible market categories. NAM is a strong example of this dynamic and represents a leader in its legal services niche, an area in which we are excited to be investing," JC Wetzel, TSCP Managing Director.