Dean Foods, a Dallas-based food and beverage company, offered more details about its planned spinoff of subsidiary WhiteWave, which produces Silk Soymilk. Dean Foods said it will keep at least 80 percent of WhiteWave after the initial public offering. The company expects to raise up to $320 million from the IPO. In conjunction with the IPO filing, Dean Foods announced preliminary third-quarter results for the WhiteWave-Alpro segment. Net sales are expected to increase 13 percent to $598 million, from $531 million in the same period in 2011. The increase in net sales was driven by continued strong volume growth across the segment’s coffee creamers and beverages and plant-based foods and beverages portfolios.