Arco Nets $958 Million From Sale of Notes: Atlantic Richfield Co. said the $988-million sale was tied to its stock in Lyondell Petrochemical Co. The offering of 39.9 million three-year exchangeable notes closed Monday. In addition to the 35 million notes sold Aug. 1, underwriters exercised their over-allotment option to purchase 4.9 million notes. The notes, priced at $24.75 each, pay a 9% interest rate and are convertible into Lyondell common stock at a 12% premium over that price. They are being traded on the New York Stock Exchange under the symbol LYX. Arco has the option of paying investors in cash or Lyondell shares when the notes mature. If it pays in stock, Arco will eliminate its 49.9% stake in the Houston-based petrochemicals company.