Main Street Announces Follow-On Investments

Invests an Additional $21.1 Million in Three Existing Lower Middle Market Portfolio Companies

HOUSTON, March 3, 2026 /PRNewswire/ -- Main Street Capital Corporation (NYSE: MAIN) ("Main Street") is pleased to announce that it recently completed follow-on investments in three existing lower middle market portfolio companies, Nello Industries Investco, LLC ("NELLO"), RFG AcquireCo, LLC ("Revolution") and Gamber-Johnson Holdings, LLC ("Gamber-Johnson"), to support strategic acquisitions.

NELLO is a manufacturer of engineered steel poles and structures for the electric utility and wireless telecommunications end markets, with products including tapered steel poles, transmission poles, lattice towers and guyed towers. Founded in 2002 and headquartered in South Bend, Indiana, NELLO's customer base consists of top EPC companies and leading electric utility and telecommunications companies. Main Street originally invested in NELLO in June 2024, partnering with the company's existing equity owners and management team to facilitate a management led buyout. This follow-on investment was made to support a strategic acquisition that broadens the company's ability to manufacture products for the electric utility substation and commercial markets. Main Street made the follow-on investment alongside its co-investor, MSC Income Fund, Inc. (NYSE: MSIF) ("MSIF"), with Main Street's investment consisting of an additional $9.2 million first lien, senior secured term loan and representing its fourth follow-on investment in NELLO since the initial partnership in 2024.

Revolution is a leading aerial survey and geospatial services company servicing blue-chip customers who service an extensive suite of end users across diverse end markets. Founded in 2006 and highly regarded for its premium services, reliability and technical expertise, the company is an established and trusted leader in the aerial survey industry. Revolution also operates two maintenance, repair and overhaul, or "MRO", facilities, providing the company with critical fleet readiness capabilities while also servicing commercial and private customers, and is also a leading resource in the Americas and Europe for the sale, purchase and lease of used and new aerial survey equipment and aircraft. Main Street originally invested in Revolution in June 2025, partnering with the company's existing equity owners and management team to facilitate a minority recapitalization. This follow-on investment was made to support a strategic acquisition that broadens Revolution's service offerings and enhances its ability to deliver advanced geospatial solutions to its customers. Main Street's follow-on investment consisted of an additional first lien, senior secured term loan of $7.5 million, representing its second follow-on investment in Revolution since the initial partnership in 2025.

Gamber-Johnson is a leading worldwide supplier of rugged mounting systems that safely secure mobile communication systems, computers and other electronic equipment in fleet vehicles, public safety vehicles, forklifts and other mobility applications. Founded in 1954 and headquartered in Stevens Point, Wisconsin, Gamber-Johnson's products are used by law enforcement, public safety, military and warehouse fleets around the globe and are known for being rugged, reliable and responsive. Main Street originally invested in Gamber-Johnson in 2016, partnering with the company's management team to facilitate a management led buyout. This follow-on investment was made to support a strategic acquisition of a weapons-retention solutions provider which enhances Gamber-Johnson's ability to serve the law enforcement market through its one-stop shop product portfolio. Main Street made the follow-on investment alongside its co-investor, MSIF, with Main Street's investment consisting of an additional $4.4 million first lien, senior secured term loan and representing its seventh follow-on investment in Gamber-Johnson since the initial partnership in 2016.

ABOUT MAIN STREET CAPITAL CORPORATION
Main Street (www.mainstcapital.com) is a principal investment firm that primarily provides customized long-term debt and equity capital solutions to lower middle market companies and debt capital to private companies owned by or in the process of being acquired by a private equity fund. Main Street's portfolio investments are typically made to support management buyouts, recapitalizations, growth financings, refinancings and acquisitions of companies that operate in diverse industry sectors. Main Street seeks to partner with entrepreneurs, business owners and management teams and generally provides customized "one-stop" debt and equity financing solutions within its lower middle market investment strategy. Main Street seeks to partner with private equity fund sponsors and primarily invests in secured debt investments in its private loan investment strategy. Main Street's lower middle market portfolio companies generally have annual revenues between $10 million and $150 million. Main Street's private loan portfolio companies generally have annual revenues between $25 million and $500 million.

Main Street, through its wholly-owned portfolio company MSC Adviser I, LLC ("MSC Adviser"), also maintains an asset management business through which it manages investments for external parties, including MSIF. MSC Adviser is registered as an investment adviser under the Investment Advisers Act of 1940, as amended.

ABOUT MSC INCOME FUND, INC.
MSIF (www.mscincomefund.com) is a principal investment firm that primarily provides debt capital to private companies owned by or in the process of being acquired by a private equity fund. MSIF's portfolio investments are typically made to support leveraged buyouts, recapitalizations, growth financings, refinancings and acquisitions of companies that operate in diverse industry sectors. MSIF seeks to partner with private equity fund sponsors and primarily invests in secured debt investments within its private loan investment strategy. MSIF also maintains a portfolio of customized long-term debt and equity investments in lower middle market companies, and through those investments, MSIF has partnered with entrepreneurs, business owners and management teams in co-investments with Main Street utilizing the customized "one-stop" debt and equity financing solutions provided in Main Street's lower middle market investment strategy. MSIF's private loan portfolio companies generally have annual revenues between $25 million and $500 million. MSIF's lower middle market portfolio companies generally have annual revenues between $10 million and $150 million.

Contacts:
Main Street Capital Corporation
Dwayne L. Hyzak, CEO, [email protected]  
Ryan R. Nelson, CFO, [email protected]                    
713-350-6000

Dennard Lascar Investor Relations
Ken Dennard | [email protected]   
Zach Vaughan | [email protected]   
713-529-6600

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SOURCE Main Street Capital Corporation