White Wave founder Steve Demos, who turned soybeans into a multimillion-dollar business and convinced consumers nationwide to give soymilk a try, has left the company in the hands of its corporate parent.

Dean Foods Co. announced that Demos resigned as president of WhiteWave Foods to pursue other interests. Dean Foods chief executive Gregg Engles will lead WhiteWave on an interim basis. The company includes WhiteWave Inc., Horizon Organic Dairy and Dean National Branded Group.

Two sources familiar with the situation said they were told during a meeting that Demos and vice president and chief financial officer Pat Calhoun were leaving the company for unspecified reasons.

Demos was offered a lesser role but declined it and resigned, one of the sources said. Calhoun, who had been with WhiteWave Inc. since its inception in 1977, is leaving voluntarily because of Demos' resignation, the source said.

Demos said he could not comment on the announcement because Dallas-based Dean Foods is a publicly traded company. He directed questions on specifics to Dean Foods.

Overall, Demos said he was appreciative of the 28 years he spent at White Wave.

"I wish WhiteWave the best. It's a purpose-driven business. It has great momentum and drive," Demos said from his Nederland home. "It was a true privilege to lead the people who have supported me for so long. I am indebted to them."

Officials at WhiteWave and Dean Foods could not be reached for comment. Dean Foods issued a brief statement announcing Demos' resignation.

Barney Feinblum, a natural products industry veteran and former president of both Horizon and Celestial, said the news was a surprise.

"The last I heard, everything was going well," he said. "I think Steve and Pat ... have done a terrific job. They didn't really need the money, but I think they felt they had the opportunity to make the world a better place."

Demos started making tofu in his bathtub nearly 30 years ago. The entrepreneur then toted the tofu around to Boulder, Colo., retailers in a red wagon.

The small venture became White Wave Inc. in 1977. Demos and Calhoun, who divorced in 1979, helped build the company that was netting $2 million a year a decade after its founding.

During the mid-1990s, the company saw its sales increase 20% annually, a growth that caught the attention of Dean Foods. The dairy company became a minority shareholder in White Wave in 1999 and, three years later, paid $192.8 million for the remaining 62.8%. The acquisition brought Dean Foods' investment in White Wave to $204 million.

The partnership launched the Boulder company into the mainstream. Since its introduction to conventional grocery stores, White Wave's Silk soymilk has become a $550 million brand.

Shortly after Dean Foods fully acquired Longmont-based Horizon Organic Dairy, it consolidated White Wave, Horizon and Dean National Branded Group and named the subsidiary WhiteWave Foods. The $1.2 billion division will be based in Broomfield.

Earlier this year, Feinblum said keeping Demos as president was a wise move and testament that Dean Foods understood the relationship between its products and customers. Now that could change, he said.

"It's a lot easier to scale up than scale down," he said. "These companies that have acquired smaller natural food companies, I think they have a hard time understanding what it takes to make a small company be successful. Without that, the vision doesn't remain."