The CFO of Houston-based National Oilwell Varco Inc. (NOV) is stepping down to become CEO of Transocean Ltd. (RIG), one of NOV’s largest customers. Effective April 22, Jeremy Thigpen will become CEO of Switzerland-based Transocean, which has its main U.S. office in Houston. Thigpen succeeds Ian Strachan, who had been serving as interim CEO since Steven Newman stepped down in February. Strachan, who is also the company's Chairman of the Board of Directors, will retire from the Board at the end of his term at the 2015 Annual General Meeting following approximately 16 years of service. Prior to joining Transocean, Thigpen spent his career in various roles at NOV and has served since 2012 as NOV's Senior Vice President and Chief Financial Officer.