Private-equity firm Energy Capital Partners announced the successful closing of a partnership with midstream asset company USD Group LLC, the company said on Sept. 22. Energy Capital Partners also declared its intention to invest more than $1 billion in additional equity in USD Group and its affiliates,

Energy Capital purchased an equity interest in USD Group’s parent entity, US Development Group LLC, the company said. Proceeds will support the shareholder base, growth projects and the balance sheet.

Houston-based USD Group LLC and its affiliates provide and operate rail logistics and other midstream infrastructure across North America.