Denise Morrison, the CEO of Campbell Soup Co. (NYSE: CPB), is retiring abruptly with no explanation. Following significant acquisitions, the company beats quarterly forecasts but lowers its outlook for the year.

Campbell, which won Mergers & Acquisitions’ M&A Mid-Market Award for 2017 Strategic Buyer of the Year, has been leveraging acquisitions to ensure the company known for comfort food for nearly 150 years remains relevant to millennials and future generations. Campbell recently closed two significant deals: the $4.8 billion acquisition of pretzel marker Snyder’s-Lance; and the $700 million purchase of organic soup maker Pacific Foods. But, like many other food producers, it faces significant challenges, including higher commodity costs and pressure to lower prices coming from Amazon.com Inc. (Nasdaq: AMZN), Walmart Inc. (NYSE: WMT) and other retailers.

Morrison’s departure leaves less than two dozen women running Fortune 500 companies, CNN Money points out. Over the past year, several high-profile women have stepped down as business leaders, including Meg Whitman of Hewlett Packard Enterprise (NYSE: HPQ). Among the female leaders still running large U.S. companies are: Mary Bara at General Motors Co. (NYSE: GM), Marillyn Hewson at Lockheed Martin Corp. (NYSE: LMT) Ginni Rometty at IBM (NYSE: IBM) and Indra Nooyi at PepsiCo Inc. (NASDAQ: PEP).

Of Morrison’s tenure at the helm of Campbell, chairman Les Vinney said in a statement: “Denise has been a passionate advocate and leader over her 15 years with the company. She has made many important contributions over the past seven years as Chief Executive Officer to reposition Campbell in the rapidly changing food industry. Denise has been able to significantly transform Campbell’s portfolio into the faster-growing snacking category with the acquisition of Snyder’s-Lance and increased the company’s focus on health and well-being with brands like Pacific Foods. Her actions have helped to enhance the long-term growth potential of Campbell.”

Morrison said: “I am proud of Campbell’s accomplishments and how we have transformed our portfolio amid changing consumer tastes for food and health and well-being. It has been an honor to lead this iconic company and exceptional team, and I am confident that Campbell will enjoy continued success for many years to come.”

Campbell has named board member Keith McLoughlin interim CEO. Meanwhile, recently elevated chief operating officer Luca Mignini is focusing on the integration of the newly acquired companies and stabilizing the company’s U.S. soup business.