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Dean Liollio Will Become Plains COO in October

The energy company veteran will step into the Chief Operating Officer role on October 2, 2026.

Updated on Sept. 29, 2026 in People

Isometric editorial illustration of a complex network of industrial oil and gas pipelines, symbolizing large-scale energy infrastructure operations.
Plains All American Pipeline has named long-time company veteran Dean Liollio as its new Chief Operating Officer, effective October 2, 2026. AI Illustration. Upload story photo >

Plains All American Pipeline and Plains GP Holdings announced that Dean Liollio will serve as the new Executive Vice President and Chief Operating Officer beginning October 2, 2026. He succeeds Chris Chandler, who is resigning from the position to pursue other interests.

Why it matters

The transition marks a leadership change within the Houston-based energy firm, placing a long-time company veteran at the helm of its operational strategy. Liollio brings decades of internal experience to the executive position as the company shifts its leadership team.

Dean Liollio is 67 years old and holds a Bachelor of Science degree in Industrial Engineering from Texas A&M University. He has served in various leadership roles at the company since 2008.

The players

Dean Liollio

He is a long-time company veteran and industrial engineering graduate from Texas A&M University who has held multiple presidential roles within the firm.

Chris Chandler

He is the outgoing Executive Vice President and Chief Operating Officer who is leaving the company to pursue other interests.

Plains All American Pipeline

It is a Houston-based energy infrastructure company that operates significant midstream assets across the United States and Canada.

The details

Liollio previously served as Senior Vice President of Special Projects for the firm from June 2024 until October 2026. His prior tenure also includes serving as President of Plains Midstream Canada from 2020 to 2024 and President of PAA Natural Gas Storage between 2008 and 2020.

Timeline

  1. Dean Liollio joined the company in 2008.

  2. He led Plains Midstream Canada starting in 2020.

  3. He became Senior Vice President of Special Projects in June 2024.

  4. The appointment was publicly announced on September 29, 2026.

  5. He assumes the role of Chief Operating Officer on October 2, 2026.

Market Landscape

The appointment follows a broader pattern of internal leadership restructuring occurring across major midstream energy firms in 2026. This move consolidates operational oversight under a veteran who has navigated both U.S. and Canadian markets for the organization.

This leadership transition is an internal corporate restructuring that is unlikely to have immediate impacts on the service or pricing experienced by retail energy customers. Clients and stakeholders can monitor the company's operational trajectory under new executive guidance via official reports.

The takeaway

The elevation of a long-term internal executive suggests a strategy focused on leadership continuity during the upcoming transition. Investors and observers often look for such internal appointments as a sign of organizational stability in the energy sector.

What happens next

Dean Liollio will officially begin his new responsibilities as Executive Vice President and Chief Operating Officer on October 2, 2026.

Further reading

For more on industry leadership changes, visit the People section.

More information

View official company details on the Plains corporate information website.