NRG Energy, the Princeton, N.J.-based power producer with $8.8 billion in 2010 revenue, named Chad Plotkin vice president of investor relations. He replaces Nahla Azmy, who is leaving to become managing director of investor relations at Energy Capital Partners. Plotkin, 36, joined NRG in 2007 as vice president of strategy and business development, a position in which he was responsible for NRG’s acquisition and integration of Energy Plus Holdings. Earlier, he served in a similar position for satellite communications company SES Americom.

Peabody Energy, the $6.8 billion St. Louis coal company, appointed Amy Schwetz vice president of investor relations. She succeeds Christina Morrow, who moved to a position in operations analytics earlier this year. Schwetz most recently served as Peabody’s vice president of financial and capital planning. She joined the company as director of compliance and accounting policies in 2005 from Ernst & Young, where she was a senior audit manager. 

CVR Energy, a $4 billion Sugar Land, Texas, energy company, named Frank Pici CFO and treasurer. He succeeds Edward Morgan, who will become executive vice president of investor relations. Pici, 55, spent the last nine years as CFO at Penn Virginia Corp., an oil and gas exploration and production company, and its related entities, Penn Virginia GP Holdings and Penn Virginia Resource Partners. Earlier, he was CFO and vice president of Mariner Energy for five years and spent seven years in senior finance roles at Cabot Oil & Gas Corp.

Tractor Supply Co., a $3.6 billion Brentwood, Tenn., farm and ranch supply retailer, appointed Christine Skold vice president of investor relations, strategic planning and Tractor Value System (TVS), the company’s continuous improvement program. She replaces Alexander Stanton, who was named senior vice president of supply chain. Skold, 41, joined the Brentwood, Tenn.-based company in 2002 as vice president of internal audit and TVS. Previously, she was assistant controller at Moll Industries and an audit manager at Arthur Andersen.

General Growth Properties, the Chicago-based shopping center owner and manager with $2.8 billion in 2010 revenue, named Michael Berman CFO and executive vice president. He succeeds Steve Douglas, who has accepted a position at Brookfield Asset Management. Berman, 53, most recently was CFO, treasurer, principal accounting officer and executive vice president at Equity LifeStyle Properties. Earlier, he was a managing director in investment banking at Merrill Lynch and an associate professor at the NYU Real Estate Institute.

Scholastic, the $1.9 billion publisher and distributor of children’s books, appointed Dennis Campagna chief accounting officer and senior vice president. He takes over the accounting role from Maureen O’Connell, who remains as the New York City company’s CFO, chief administrative officer and executive vice president. Campagna, 50, most recently was regional controller at Clear Channel Communications. Previously, he spent 15 years in business and finance positions at Time Inc. and was a senior audit manager at PricewaterhouseCoopers.