US-based infrastructure investor I Squared Capital has entered into an agreement to purchase Spire’s natural gas storage facilities in Wyoming and Oklahoma for $650m.
The natural gas storage assets included in the sale comprise Spire Storage West, with two fields in south-western Wyoming authorised for up to 55 billion cubic feet (bcf) of working gas capacity, mainly serving western US customers.
Another asset included in the deal is Spire Storage Salt Plains in Oklahoma, which provides 17bcf of working gas capacity to mid-continent and mid-western US markets, with connections to the Southern Star Pipeline and Oklahoma Gas Transmission.
I Squared stated that it plans to support the growth of the storage platform, improve operations, and pursue new expansion opportunities to meet increasing demand for natural gas storage in the western and mid-continent regions.
I Squared chief investment officer Gautam Bhandari said: “These assets represent a high-quality, strategically located infrastructure platform that plays a critical role in supporting energy reliability across key US markets.
“We see significant opportunity to build on Spire’s strong foundation, leveraging the platform’s contracted cash flows, strategic connectivity and expansion potential to meet growing demand for reliable and flexible energy solutions.”
The consideration is made up of a $600m cash payment when the transaction closes and an additional deferred payment of $50m scheduled for Spire’s 2027 fiscal year.
The agreement comes as Spire seeks to partially finance its recent acquisition of Piedmont Natural Gas’ Tennessee business, which was finalised on 31 March 2026 at a cost of $2.48bn.
The acquisition, integrated as Spire Tennessee, adds more than 200,000 customers and almost 3,800 miles of distribution and transmission pipelines, consolidating Spire’s position across Missouri, Alabama, Mississippi, and now Tennessee.
Greenhill, a Mizuho affiliate, acted as financial adviser to Spire on the I Squared transaction, with Vinson & Elkins as Spire’s legal counsel. Kirkland & Ellis provided legal advice to I Squared.
The deal is expected to complete in the second half of Spire’s 2026 fiscal year. The closing is subject to regulatory approvals and the expiration or termination of the applicable Hart-Scott-Rodino Antitrust Improvements Act waiting period.
Spire president and CEO Scott Doyle said: “This transaction represents another important step in sharpening our focus on our core regulated natural gas utility businesses.
“Our gas storage assets have played an important role in serving customers across the Midwest, Rockies and Western US, and we appreciate the dedication of the employees who have contributed to their success.
