Middle market private equity firm
Sterling Investment Partners
- HeadquartersGreenwich, CT S1
- Founded1991 S1
- Websitesterlinglp.com
- Last verifiedOctober 19, 2026
At a glance
| Latest fund | Sterling Investment Partners V, $1.6B (Nov 2025) S4 |
|---|---|
| EBITDA range | $15M to $50M S2 |
| Revenue range | $50M to $500M S2 |
| Check size | $100M to $450M S1 |
| Deal types | Platform, Add-on S4 |
| Geography | United States S2 |
| Sectors | Distribution, IT Services & MSP, Cybersecurity, Construction Services, Accounting & Professional Services |
What Sterling Investment Partners buys
Sterling Investment Partners has backed middle market companies from Greenwich, Connecticut since 1991 and sticks to two areas. In distribution it favors aftermarket and MRO parts and consumable products; in business services it favors building and facilities services and other essential work that customers outsource. It wants market leaders with recurring demand, room to grow through acquisitions and owners committed to the next stage. Current platforms include Cyber Advisors, a managed IT and security provider bought in March 2026, utility vegetation manager XKIG, environmental consultant Verdantas, federal services firm Markon, restoration and facility services company Camp, and distributors Aurora, Banner Industries and Mr. Greens.
The firm targets companies with $50 million to $500 million of revenue, $15 million to $50 million of EBITDA and enterprise values of $150 million to $500 million, and it invests $100 million to $450 million of equity per deal. It buys control and closed its fifth fund at a $1.6 billion hard cap in November 2025. Most owners of smaller companies will meet Sterling as an add-on, which it accepts at any size.
Recent deals
Announced in the 24 months before October 19, 2026.
| Date | Company | Type | Sector | Source |
|---|---|---|---|---|
| Mar 2026 | Cyber AdvisorsMaple Grove, Minnesota managed security and managed IT provider with more than 1,800 customers | Platform | IT Services & MSP | Source |
| Feb 2026 | Millennium CorporationDefense cyber operations and engineering firm added to Markon | Add-on | Cybersecurity | Source |
| Jan 2026 | PACE EngineersKirkland, Washington engineering, surveying and environmental consulting firm added to Verdantas | Add-on | Source | |
| Nov 2025 | PLEX SolutionsCybersecurity, AI and secure systems engineering firm added to Markon | Add-on | Cybersecurity | Source |
| Nov 2025 | Sterling Investment Partners VClosed at its $1.6 billion hard cap, above a $1.25 billion target | Fund close | Source | |
| Oct 2025 | XKIGUtility vegetation management platform recapitalized through Sterling's first single-asset continuation vehicle, with Fund V investing alongside | Investment | Source | |
| Jan 2025 | Parishables Food ServiceLocally owned Atlanta produce and dairy distributor added to Mr. Greens | Add-on | Distribution | Source |
| Jan 2025 | Civil West Engineering ServicesCoos Bay, Oregon water and municipal engineering firm added to Verdantas | Add-on | Source | |
| Jan 2025 | M-H-MMarysville, California water and land development engineering firm added to Verdantas | Add-on | Source | |
| Dec 2024 | Leverage Information TechnologiesVirginia software engineering and data science consultancy added to Markon | Add-on | Source | |
| Nov 2024 | Groundwater Sciences CorporationNortheast site assessment and groundwater remediation consultant added to Verdantas | Add-on | Source | |
| Nov 2024 | PROtectWichita testing, inspection and compliance services provider; management and employees keep significant equity | Platform | Source | |
| Oct 2024 | ASEC EngineersDenver power delivery and substation engineering firm added to Verdantas | Add-on | Source |
Portfolio by sector
From the firm's portfolio page S3.
Business Services
- AIMS Companies
- Camp
- Cyber Advisors
- Markon Solutions
- PROtect
- Verdantas
- XKIG
Distribution
- Aurora Parts and Accessories
- Banner Industries
- Mr. Greens
Past investments: Aavid Thermal Technologies, All My Sons Moving and Storage, American Buildings Company, American West Restaurant Group, Anser Advisory, Cambridge International, CBORD Group, Euro Outlet Malls, Excelligence Learning Corp, Fairway Group Holdings Corp, FCX Performance, GPX International Tire, HeartLand, Interline Brands, Kenan Advantage Group, Lazer Spot, Lipari Foods, Marcone, Miller Heiman, Power Stop, Service Logic, Survey Sampling International, Tidewater Barge Lines, U.S. Maintenance, U.S. Shipping Partners L.P., Ubique Group, Washington Inventory Service
Greymont’s take
How Sterling Investment Partners fits a seller
Sterling is a fit for larger founder-led companies, roughly $15 million of EBITDA and up, in distribution or recurring business services. Founders and managers often keep a stake: at PROtect, management and employees kept significant equity. Most smaller owners will deal with a Sterling platform rather than the firm itself, and those platforms buy often. Verdantas added five engineering and environmental firms between October 2024 and January 2026, Markon bought three federal technology and cyber firms, and Mr. Greens bought a locally owned Atlanta distributor.
Sterling also holds winners for a long time. In October 2025 it moved XKIG into a continuation vehicle rather than selling it. Ask which fund holds the platform you would join, how long Sterling expects to own it, and whether you would roll equity into that platform.
Questions owners ask
What size company does Sterling Investment Partners buy?
Its criteria call for $50 million to $500 million of revenue, $15 million to $50 million of EBITDA and enterprise values of $150 million to $500 million. Add-on acquisitions for its platforms can be any size.
Does Sterling invest in IT services or cybersecurity companies?
Yes. In March 2026 it bought Cyber Advisors, a Minnesota provider of managed security, cybersecurity consulting and managed IT services. Its federal services platform Markon has also bought cyber and technology firms, including PLEX in 2025 and Millennium in 2026.
How much capital does Sterling have to invest?
Its fifth fund closed in November 2025 at its $1.6 billion hard cap, above a $1.25 billion target. The firm says it has invested more than $3.2 billion across more than 290 transactions since 1991.
Sources
- S1Sterling Investment Partners home page (at a glance) Accessed October 19, 2026
- S2Sterling Investment Partners: Investment Criteria Accessed October 19, 2026
- S3Sterling Investment Partners: Companies (current and realized) Accessed October 19, 2026
- S4Sterling Investment Partners Closes Over $1.6 Billion in Oversubscribed Fifth Fund (November 20, 2025) Accessed October 19, 2026
- S5Sterling Investment Partners: About Us Accessed October 19, 2026
- S6Sterling Investment Partners: News Accessed October 19, 2026
- S7Sterling Investment Partners Receives Strategic Minority Investment from PACT Capital Partners (October 15, 2026) Accessed October 19, 2026
Compiled by Greymont Advisors from public sources, including the firm’s own website and press releases. Greymont is not affiliated with Sterling Investment Partners. Figures are as reported on the dates shown and may have changed. Request a correction