United Airlines' C-E-O is telling employees today that a Chapter Eleven bankruptcy filing is, using his words,"more likely." Glenn Tilton's recorded message to the airline's 83-thousand workers says Chapter Eleven is a more likely outcome because it will allow the airline to restructure and to continue operating. United is Denver's largest carrier, and the nation's Number 2 carrier. Shares in United parent U-A-L Corporation are trading at about 80 cents each on the New York Stock Exchange today as investors anticipate the filing. Sources speaking on condition of anonymity tell The Associated Press that United is preparing to file on Sunday. The U-A-L board of directors meets tomorrow.