Devon Energy Corp. President and CEO John Richels, 63, is retiring effective July 31, with COO Dave Hager slated to take the helm. Richels is to become chairman in 2016 when co-founder Larry Nichols, 72, retires and becomes chairman emeritus, the board of directors said. "John's vision and leadership have delivered significant value to Devon shareholders for many years and particularly as we recently repositioned and rebalanced the company as a leading North American exploration and production company," said Nichols. Hager, 58, "has been instrumental in the rebalancing of our portfolio and his focus on creating shareholder value, his integrity and his many other positive attributes will serve all stakeholders well," said Richels, who joined Devon in 1998. Richels was elected president in 2004 and named CEO in 2010 when Nichols retired. Hager joined Devon in 2009 as executive vice president of exploration and production. Hager previously worked forAnadarko Petroleum Corp. predecessor Kerr-McGee Corp. He has a bachelor's degree in geophysics from Purdue University and a master's degree in business administration from Southern Methodist University.