Sunnyvale, Calif. -- Time Warner plans to block the possible appointment of Jon Miller, the former chairman of AOL, to Sunnyvale-based Yahoo's board of directors, TechCrunch reported. Citing unnamed sources, the web site reported that Miller would require Time Warner's approval to serve on the board, since he remains under a non-compete agreement with AOL. Yahoo must select its new board members by Aug. 15. The news comes as a blow to Yahoo executives, including CEO Jerry Yang, who are attempting to install several qualified outsiders to the board as part of an agreement with activist investor Carl Icahn. Reports have circulated of late that Time Warner is in discussions to possibly sell AOL to Yahoo.