Diameter Capital Partners LP
Diameter named in Delfin Midstream first FLNG final investment decision
Summary: Delfin Midstream announced a $5 billion final investment decision for its first floating LNG vessel and said a group including Diameter Capital Partners is providing additional investment. Diameter's own public media page also points to the Delfin FLNG financing announcement.
Why it matters: The update may matter to due-diligence readers as a public signal of Diameter's participation in a private energy-infrastructure financing, while requiring clear caveats that the source does not establish fund-level exposure size, economics, credit quality, or investment merit.
Summary
Delfin Midstream announced that it had taken a $5 billion final investment decision for the first floating liquefied natural gas vessel in the Delfin LNG project. The Delfin source-party release says the additional-investment group included Global Infrastructure Partners, Mitsui O.S.K. Lines, Vitol, and Diameter Capital Partners.
Diameter’s public media page points readers to the Delfin floating-LNG financing announcement, and the Delfin release quotes Diameter co-founders and managing partners Scott Goodwin and Jon Lewinsohn on the milestone. This post treats the item as a source-party project-finance update involving Diameter, not as a view on LNG markets, project credit quality, fund economics, or investment merit.
Why it matters
For due-diligence readers, the update is relevant because it places Diameter in a public source-party announcement for a large private energy-infrastructure financing. That can help frame follow-up questions about the firm’s private credit and infrastructure-related activity, its stated role in source-party financings, and how future manager or issuer disclosures describe the commitment.
The source does not provide enough basis to infer Diameter’s fund-level exposure, sizing, expected returns, current mark, risk allocation, or broader energy-market posture. This post should not be read as an endorsement of Diameter, Delfin, LNG infrastructure, or any related security or private investment.
Source notes
- Diameter public homepage/media area: https://diametercap.com/
- Delfin source-party PDF announcement: https://delfinmidstream.com/wp-content/uploads/2026/06/Delfin_FID-Press-Release.pdf
- SEC submissions identity context for Diameter Capital Partners LP: https://data.sec.gov/submissions/CIK0001727012.json
- Public AdviserInfo identity reference: https://adviserinfo.sec.gov/firm/summary/289307
- Source posture: the controlling event source is the Delfin PDF, supported by Diameter’s manager-hosted media pointer. SEC and AdviserInfo links are identity and filing-context references only.
9AT filing context
Public SEC identity context maps Diameter Capital Partners LP to CIK 1727012, and public AdviserInfo context maps the adviser lane to CRD 289307. Public adviser-profile context describes Diameter as an alternative asset manager with about $28.8 billion in ADV-reported profile scale.
The SEC submissions feed also shows a Form 13F-HR/A filed on 2026-08-14 for report date 2026-06-30. That is included only as narrow public filing-recency context. The 13F package was not used here for table rows, reported values, issuers, option-like details, or any claim about Delfin, because Form 13F covers selected long U.S.-listed equity securities and related reportable instruments; it does not capture private-project exposure, complete portfolio exposure, AUM, performance, or investment intent.
What to watch
Watch for additional Delfin source-party updates on later project milestones, financing participants, vessel construction, permits, offtake, and subsequent FID timing. Also watch Diameter-authored or regulatory sources for any public explanation of how the firm frames private credit or infrastructure-related participation, without treating third-party project announcements as manager rationale beyond what they explicitly state.