Unit Corp. elected David T. Merrill to serve as its next CEO and president, the Tulsa, Okla.-based diversified energy company said in a Feb. 21 news release.

Effective April 1, Merrill will succeed Larry D. Pinkston, who has decided to retire from his CEO and president roles but will remain on Unit’s board of directors.

Merrill joined Unit, which is engaged through its subsidiaries in E&P, contract drilling and gas gathering and processing, in August 2003. The company’s E&P subsidiary, Unit Petroleum Co., operates primarily in the Midcontinent in the Anadarko and Arkoma basins.

Initially, Merrill served as the company’s vice president of finance until February 2004 when he was named CFO and treasurer, positions he held until November 2017. He has served as COO since August 2017.

In a statement, Merrill thanked Pinkston for his leadership and counsel over Merrill’s nearly 17 years with the company adding: “As we move forward, we will focus on overcoming the challenges that our company and industry face.”

Pinkston has served as Unit CEO since April 2005. He began his career with Unit in December 1981 and was named CFO in May 1989. He assumed the office of president in August 2003. In 2004, he was elected to the position of COO in February 2004 and also joined the board as a director.

Commenting on Pinkston’s retirement, Unit Board Chairman Michael Adcock said in a statement: “In his many roles, Larry strived to achieve the best results for both the company and its shareholders. After nearly 39 years of service, Larry’s retirement is very well deserved.”