FirstEnergy Corp., a $16 billion diversified energy company, appointed James Pearson CFO and senior vice president. He succeeds Mark Clark, who will become executive vice president of finance and strategy. Pearson most recently served as treasurer and senior vice president of the Akron, Ohio-based company. Since joining FirstEnergy in 1976, he has held positions including group controller for a subsidiary, First Energy Solutions. Steve Staub, the company’s assistant treasurer and executive director, will replace Pearson as treasurer. Staub was also named vice president. He has been assistant treasurer since First Energy’s 2011 merger with Allegheny Energy and had been Allegheny’s assistant treasurer since 2007. Earlier, Staub worked at Duquesne Light and Ford Motor Co.