NEW YORK _ A federal grand jury in Manhattan returned a 238-count indictment Wednesday charging the Saudi exile Osama bin Laden with conspiring to bomb two U.S. embassies in Africa in August and with committing acts of terrorism against Americans abroad. The warning forecast the Aug. 7 bombing in several particulars, the officials said. NEW YORK _ Several months after the bombing of the World Trade Center in February 1993, one of the suspects tried to bargain with federal prosecutors in New York, offering inside information about the bomb plot in exchange for a lighter sentence.