Fresh off his retirement from American Airlines, former Chairman and President Gerard Arpey will join a private equity real estate firm founded by another former airline executive. Arpey will become a partner effective Friday in Emerald Creek Group, based in Houston. Larry Kellner, former Continental Airlines chairman and CEO, founded the firm as he exited from the air travel industry in 2009. Kellner had served as executive vice president and chief financial officer of real estate investment and construction firm The Koll Co. before his time at Continental. The move for Arpey comes as American and its parent company, AMR Corp. (AMR) filed for Chapter 11 bankruptcy protection Tuesday morning. Arpey told AMR of his decision to retire on Monday. "I have known Gerard for many years, and watched with admiration as he led American Airlines … through the most challenging decade in the history of the airline industry," Kellner said in a release. Arpey joined American in 1982 as a financial analyst and worked in multiple roles with the company. Write to Andrew Scoggin. Follow him on Twitter @ascoggin.