Plastics and fiber manufacturer Eastman Chemical Co., which has been plagued by falling revenues for more than three years, announced a major reorganization this morning. Starting Sept. 1, the company will be divided into a polymers group, headed by J. Brian Ferguson; and a chemicals group, headed by Allan R. Rothwell. Both will report to CEO and chairman Earnest W. Deavenport Jr., who will be joined in the newly created "Office of the CEO" by R. Wiley Bourne Jr., vice chairman and executive vice president; James L. Chitwood, senior vice president and chief technology officer; and Darryl Williams, senior vice president. Kingsport, Tenn.-based Eastman reported revenues of $4.5 billion in 1998, down from $4.7 billion in 1997, and $5 billion in 1995. In the most recent fiiscal quarter ending in June, the company reported revenues of $1.12 billion, down from $1.17 billion for the same quarter last year. "Our new organizational structure was driven by three major factors -- customer focus, accountability, and efficiency," Deavenport said in announcing the changes. "This structure puts our work groups together in a way that makes it easier for employees to develop a sharper customer focus and a greater understanding of how to create value for both our customers and our company."