How Milane built the fortune
Milane Frantz is one of four children of Dan Duncan, a Texas entrepreneur who started a small propane distribution business and turned it into one of the largest energy infrastructure companies in North America. Her wealth is inherited. When Duncan died in March 2010, his controlling interest in Enterprise Products Partners passed into a structure of family trusts and holding entities, and his four children became its principal beneficiaries.
The value of that inheritance rests on a business that collects fees for moving and processing hydrocarbons rather than on drilling for them. Enterprise owns tens of thousands of miles of pipelines, storage caverns, processing plants and export terminals along the Gulf Coast and across the country. Because much of its income comes from long-term contracts and volumes rather than commodity prices, the partnership has paid steady cash distributions to unitholders for decades, and the Duncan family, as the largest holder, receives a large portion of them.
Duncan's death came during the one year in which the United States federal estate tax had lapsed, a fact widely noted at the time because it allowed the estate to pass to his heirs without that tax.
The partnership kept expanding after Duncan's death. It built new fractionation capacity, export terminals for liquefied petroleum gas and ethane, and petrochemical units that turn natural gas liquids into propylene. Each of those projects added to the fee-based income that underpins the family's stake, so the inheritance has grown with the asset base rather than sitting as a static pile of cash.
Companies and holdings
The core holding is the family's stake in Enterprise Products Partners, a publicly traded master limited partnership listed on the New York Stock Exchange. The family owns its units through a group of entities that Dan Duncan set up during his lifetime, and the general partner of the partnership remains under family control. Milane's sister Randa Duncan Williams serves as chair of the general partner.
The partnership's main businesses include:
- natural gas liquids pipelines, storage and fractionation, centred on Mont Belvieu, Texas
- crude oil and refined products pipelines and terminals
- petrochemical plants and Gulf Coast export docks
Public filings indicate that family members, rather than outside investors, hold the voting control over these entities.
Several large mergers shaped the company the family now owns. Enterprise combined with GulfTerra Energy Partners in 2004, absorbed TEPPCO Partners in 2009, and in 2010 merged with Enterprise GP Holdings, the separate public entity that had held the general partner interest. That last step simplified the structure and left the Duncan heirs with a single, very large position in one listed partnership.
Early life and career
Milane Frantz grew up in Houston during the years her father was building Enterprise from a modest regional operation into a major company. Dan Duncan had started the business in 1968 with very little capital and a pair of delivery trucks, and by the time his children were adults it had become a public partnership with assets in many states.
Unlike some heirs of family companies, Frantz has kept a private profile, and few details about her education or professional career have been reported in depth. She lives in Houston, where the company is still headquartered, and her public role is mostly tied to the family's ownership and its charitable activity rather than to day to day management of the business.
Philanthropy and public life
The Duncan family is closely associated with Houston's medical and cultural institutions. During his lifetime Dan Duncan made very large gifts to Baylor College of Medicine and to Texas Children's Hospital, and the cancer centre at Baylor carries his name. His heirs have continued to support causes in the city through family foundations.
Milane Frantz herself rarely gives interviews and does not publicize her personal giving, so much of her philanthropic activity is not visible in public records. She is generally described as one of the quieter members of a family that prefers to let the partnership's leadership speak for the business.