Private company
Who owns Quest Diagnostics Venture LLC
One company in the researched set discloses a stake in Quest Diagnostics Venture LLC, none of it sized by anyone who discloses it. Quest Diagnostics Venture LLC is private, so no 13F reports it: a 13F covers exchange listed positions only. These figures exist because each holder disclosed the stake in its own filings.
Quest Diagnostics Venture LLC - Profile
- Type
- joint venture
- Based in
- United States
Quest Diagnostics Venture LLC is a Pennsylvania limited liability company that serves as the holding vehicle for the Erie clinical laboratory partnership known as ACL, Associated Clinical Laboratories. It holds the majority interest in Associated Clinical Laboratories of Pennsylvania, L.L.C., which is the general partner of Associated Clinical Laboratories, L.P., the entity that actually runs the laboratory. ACL was established in 1986 and operates as a regional reference laboratory from Erie, Pennsylvania, running routine and specialised diagnostic testing for physicians, hospitals and patients across northwestern Pennsylvania, Chautauqua County in New York and Ashtabula County in Ohio, through a central laboratory and a network of patient service centres including sites inside local hospital campuses. The structure exists because the laboratory is co-owned with regional hospital interests rather than held outright.
Source
Quest Diagnostics Venture LLC files nothing with the SEC, so none of this comes from a filer record. The description was written for this site in August 2026 from Quest Diagnostics Incorporated 2025 Form 10-K, Exhibit 21.1 subsidiaries of the registrant (SEC EDGAR), ACL, Associated Clinical Laboratories and Associated Clinical Lab, West Ridge patient service centre (Quest Diagnostics locations). The ownership figures below come from the holders' filings instead, and are sourced row by row.
The disclosed stakes
One row per position. Where a holder reports the same company in two share classes, both rows are shown rather than summed, because the class is part of a position's identity.
Where each figure comes from
A private stake has no ownership form behind it, so the source is always the holder's own filing or disclosure. Anything modelled says so, with the arithmetic.
- Quest Diagnostics Incorporated. Exhibit 21.1 lists 'Quest Diagnostics Venture LLC (PA)' at 51%, held via the wholly-owned Quest Diagnostics of Pennsylvania Inc., written here as 51, not 0.51. Majority interest, part of the same Pennsylvania cluster as Associated Clinical Laboratories of Pennsylvania, L.L.C. and Associated Clinical Laboratories, L.P. below (all three are siblings under Quest Diagnostics of Pennsylvania Inc. in the exhibit's structure, not a parent-child chain of each other). No individual carrying value disclosed. source
What this page is not
It is not a complete register. It lists the holders who happen to be inside the researched set and disclosed the stake themselves. A private company can have many other shareholders, and nothing here rules them out: venture investors, founders and employees usually appear in no public filing at all. Percentages are of Quest Diagnostics Venture LLC where a holder stated one, and are missing where no holder did.