Arco, Exxon, Mobil, Phillips Announce Aurora Discovery in Prudhoe Bay Area ANCHORAGE, AK, March 23, 1999 (PRIMEZONE) -- ARCO Alaska, Inc. (NYSE: ARC), Exxon Company USA (NYSE: XON), Mobil Alaska E&P Inc. (NYSE: MOB), and Phillips Petroleum Company (NYSE: P) today...