HCG Associates (backed by Southfield Capital) Acquires Protexus

Promus Capital Management Acquires Tersus Solutions

December 19, 2025

Environmental Services

Promus Capital Management, a Chicago-based private investment firm, has completed the acquisition of Tersus Solutions, a Colorado-headquartered provider of proprietary liquid CO₂ waterless cleaning, recommerce, and repair services. Promus plans to support Tersus' growth by investing in additional CO₂ machines and capacity, expanding commercial efforts, and scaling the company's recommerce, fire PPE cleaning, and down recycling capabilities.

Southfield Capital Partners with Protos Security

March 6, 2019

Professional Services

Southfield Capital has partnered with Protos Security, a tech-enabled managed security services provider, in a control investment to support the company's next phase of growth. Protos' co-founders Chris Copenhaver and Patrick Henderson will remain in leadership roles; Monroe Capital provided debt financing and Pepper Hamilton served as legal counsel to Southfield. The investment will accelerate Protos' software development and expansion into new markets while leveraging its large vendor network and enterprise client base.

Planned Systems International Acquires ProSphere Tek

July 22, 2021

IT Services

Planned Systems International (PSI) has acquired ProSphere Tek, a mid-tier technology integrator serving federal customers. The acquisition expands PSI’s contract and customer portfolio and adds capabilities in cybersecurity, cloud/network operations, and health IT operations to strengthen its federal health and defense offerings.

Prototek Acquires Prototype Solutions Group

August 3, 2022

Manufacturing

Prototek Holdings LLC has acquired Prototype Solutions Group (PSG), a Menomonie, Wisconsin-based rapid prototyping provider, expanding Prototek's CNC, additive and cast manufacturing capabilities and Midwest capacity. PSG founder Alan Anderson will serve as a strategic operational advisor and will continue to lead day-to-day operations at the Menomonie location; terms were not disclosed.

Kelvin Group Merges JS Compliance and HCG Associates to Form Sotera

January 20, 2026

Industrial Services

Kelvin Group, a Southfield Capital portfolio company, announced the merger of JS Compliance and HCG Associates to create Sotera, an industrial refrigeration compliance platform. The combined platform delivers Process Safety Management (PSM), Risk Management Program (RMP), and Ammonia Refrigeration Management (ARM) services to regulated industrial and food processing customers across the United States.

H.I.G. Capital Acquires Majority Stake in Protos S.p.A.

March 11, 2025

Engineering Services

H.I.G. Capital, through an affiliated vehicle, has acquired a majority stake in Protos S.p.A., a leading Italian technical advisory and engineering consultancy. The investment — made in partnership with Protos' management — aims to accelerate the company’s growth in Italy and internationally, leveraging its capabilities in inspections, certifications, engineering, environmental/ESG advisory and related technical services.