Yahoo! Inc. plans to make changes in its top leadership. The company's action will award an important role to Susan Decker, its chief financial officer, by giving her oversight of the firm's main revenue-generating activities. These include Yahoo!'s online-advertising sales teams. The move also means the departure of Dan Rosenweig, chief operating officer, among other executives. Yahoo! is taking these actions as it attempts to address its falling share price, slowing revenue growth, and dissent in the ranks. The new corporate structure is designed to increase accountability and speed up the decision-making process. This is in response to criticism that the firm has acted slowly and not held its executives responsible for poor company performance. The reorganization will likely go into effect on January 1, 2007. Ms. Decker will continue in her role as chief financial officer until a successor is found. Some industry analysts speculate that Decker, a former equity analyst who came to Yahoo! as its chief financial officer in 2000, is being tested as a potential successor to Terry Semel, chief executive officer. Semel is 64 years old and could retire soon. Rosenweig plans to leave his job at the end of March 2007. Yahoo! is looking for an executive to head up its 'Audience' group as well. This group includes products in areas like search, media, communities, and communications.