PLO CHAIRMAN Yasser Arafat's guerrillas battled followers of a breakaway officer in fighting Friday that killed at least 17 combatants and wounded 40 in southern Lebanon, police said . . . ALASKA NATIVES, commercial fishermen, businesses and property owners in the Prince William Sound region are eligible to collect damages from the 1989 Exxon Valdez oil spill, a state judge ruled Thursday in Anchorage . . . THE MEDELLIN cocaine cartel has kidnapped a cousin of Colombia President Cesar Gaviria, police have confirmed in a report that could signify another blow to the government's anti-drug war.