In Business This Week
-- Carl Icahn, like buddy Bennett LeBow, is seeking up to 15% of RJR Nabisco's shares.
-- Stephan Weiss, husband of Donna, resigned as co-CEO of Donna Karan Co.
-- MCI Communications will pay $1 billion for SHL Systemhouse.
-- The Senate Banking Committee agreed to combine bank and thrift charters by 1998.EDITED BY KEITH H. HAMMONDS