Plains All American Pipeline LP and Plains GP Holdings have appointed Dean Liollio as executive vice-president and chief operating officer, effective Oct. 2, 2026.

Liollio succeeds Chris Chandler, who is resigning from the company to pursue other interests, Plains said in a release Sept. 29. Chandler joined Plains in 2018 after holding leadership roles at Phillips 66, and his tenure spanned a period in which the midstream operator expanded its Permian crude gathering and takeaway portfolio.

Liollio brings deep operating experience across the midstream value chain, much of it built within Plains itself. He most recently served as senior vice-president, special projects. Before that, he was president of Plains Midstream Canada from 2020 until 2024 — a business that runs the operator's Canadian crude oil marketing and pipeline systems — and earlier held simultaneous leadership of two gas-focused units: president of PAA Natural Gas Storage from 2008 until 2020 and president of Plains Gas Solutions from 2016 until 2020.

His career before Plains, which he joined in 2008, included executive roles as president, chief executive officer and director of EnergySouth Inc., and as president and COO of CenterPoint's natural gas distribution operations across a five-state area.

The handover places a pipelines-and-terminals veteran with both Canadian and U.S. gas and liquids credentials atop Plains' operating organization at a time when the partnership continues to manage its NGL and crude logistics footprint. The effective date of Oct. 2, 2026 marks the transition point; the watch item is how quickly Liollio's operating agenda — and any portfolio moves that follow Chandler's exit — becomes visible under the new structure.