July 14 (Reuters) - Plant-based milk maker Oatly said on Tuesday it raised a $200 million equity investment from a group led by Blackstone Group Inc BX.N that includes celebrities Oprah Winfrey, Natalie Portman and former Starbucks Corp SBUX.O chief Howard Schultz.

The new investors, also including rapper Jay-Z&aposs entertainment company Roc Nation, Orkila Capital and Rabobank&aposs Rabo Corporate Investments, will join the company&aposs existing partners and its founders - brothers Rickard and Björn Öste - who will also reinvest with additional capital.

The plant-based food sector is a fast growing category that has gained investors&apos attention over the past few years, especially as fast-food chains and upscale restaurants create new menus to attract health- and environment-conscious diners.

Sweden-based Oatly, known for its oat milk products, has tie-ups with several cafes in the United States, including Starbucks, to make plant-based coffee and tea, and also sells its products online and in retail stores.

Much of the demand for plant-based food is being led by millennials and generation Z consumers, who are more than willing to spend on sustainable products that are also healthy.

Oatly said the proceeds from the latest investment will be used to fund its expansion projects in current markets and to set up new production plants and create jobs in Europe, the United States and Asia.

Earlier this year, California-based almond milk maker Califia Farms also raised investments worth quarter of a billion dollars, underscoring a huge interest in the plant-based food sector.