For Immediate Release November 24, 1998 ARCO BOARD ELECTS THREE VICE PRESIDENTS LOS ANGELES - The Board of Directors of ARCO elected three corporate vice presidents. The three include Dennis Schiffel as Vice President, Corporate Planning; Beverly Thelander as Vice President, Communications, Public Affairs, and Investor Relations; and Stephen G. Suellentrop as Vice President, Technology and Operations Services. Schiffel, 55, who previously served two years as ARCO's Vice President of Investor Relations, succeeds Donald R. Voelte, who was elected Executive Vice President, in September. Since first joining ARCO in 1979, Schiffel held a variety of planning and finance positions in London and Hong Kong as well as ARCO offices in the United States. He earned a bachelors of science degree from Ohio State University, a master of business administration in economics from Indiana University, a master of arts and Ph.D. in economics from Claremont Graduate School and JD from George Washington University. Thelander, 43, assumed new responsibilities combining ARCO's worldwide Communications, Public Affairs and Investor Relations after serving as Vice President of Wholesale Marketing, Distribution and Supply for ARCO Products, the company's refining and marketing division. She joined ARCO in 1981 and held various financial positions in ARCO Products as well as the company's corporate finance department and transportation unit before moving into the wholesale marketing position in 1996. She is a graduate of UCLA where she earned a bachelors degree in economics and a masters degree of business administration in finance. VICE PRESIDENTS ELECTED Page 2 Suellentrop, 46, is responsible for a new function, headquartered in Plano, Texas, which includes Engineering and Technology; Environment, Health & Safety; Information Technology; Procurement, and ARCO Environmental Remediation Ltd. He was managing director at ARCO British Limited and ARCO's vice president for Europe and North Africa before assuming his new position. He joined ARCO in 1975 and held a number of engineering and operations positions before moving to the United Kingdom in 1994. Suellentrop completed his bachelors of science and masters of science degrees in petroleum engineering at the University of Missouri, Rolla. ARCO (NYSE: ARC) is a worldwide integrated hydrocarbons company with operations encompassing all aspects of the oil and gas business: exploration, production, and marketing of crude oil, natural gas and natural gas liquids, and the refining, marketing and transportation of petroleum products. ARCO has significant operations on the North Slope of Alaska and in the Gulf of Mexico, the Permian Basin, China, Indonesia, the North Sea and North Africa. ### CONTACT: Linda Dozier, 213-486-3384 or Marylou Flynn, 213-486- 8263. For a menu of ARCO new releases or to retrieve a specific release, visit our web site at http://www.arco.com on the Internet.