The State Department has ordered the expulsion of a Soviet trade representative in retaliation for the "unwarranted expulsion" of a U.S. military officer from the Soviet Union, State Department officials said Thursday. The officials said the Soviet Embassy was informed Wednesday by Secretary of State James Baker that Sergei Malinin, an accredited diplomat working for the Soviet trade organization known as Amtorg, must leave the United States by the end of the month. State Department officials said, "This is in response to the unwarranted expulsion from the Soviet Union of Lieutenant Colonel Daniel Van Gundy."