National Oilwell Varco Inc . (NYSE: NOV) appointed Clay C. Williams as its president and CEO, the company said Feb. 27.

Williams was on the board of directors since November 2013, and was president and chief operating officer since December 2012, the company said.

Previously, Williams was the company’s executive vice president and chief financial officer, National Oilwell Varco added.

The company had previously announced that Merrill “Pete” Miller would step down as CEO and chairman of the board, the company said.

"Pete has built an incredible organization at National Oilwell Varco, one that has benefitted our customers, suppliers, employees and shareholders. He has been an inspiring leader for our team, and I look forward to building upon the traditions of diligence and excellence that have been created here,” Williams said.

National Oilwell Varco, based in Houston, is an oil and natural gas upstream services company operating internationally.