AT&T Corp. could be forced to shed its stake in Time Warner Entertainment or Liberty Media Group Inc. to win approval of its $59-billion purchase of MediaOne Group Inc., people familiar with the discussions said. AT&T, soon to be the largest U.S. cable-television company, has been trying for months to convince the Federal Communications Commission that it should be able to keep Liberty, its programming subsidiary, and its 25% stake in Time Warner Entertainment once the MediaOne purchase closes. Combined, AT&T and MediaOne would serve about 40% of households with cable-TV or satellite service. The FCC's staff is concerned this scope and Liberty's programming assets could give the new company too much control of its industry. The staff has recommended that the commission force the company to shed key assets to reduce its dominance. FCC Chairman William Kennard is considering scheduling a vote at the agency's May 15 meeting. AT&T, based in New York, and the FCC had no comment.