Overview

When DuPont bought petroleum manufacturer Conoco, Inc. in 1981, it was the largest merger in corporate history. The purchase gave DuPont a secure source of petroleum feedstocks needed for many of its fiber and plastics operations. Conoco also manufactured profitable commercial petroleum products and coal, produced by the wholly owned subsidiary Consolidated Coal Company. DuPont sold all of its Conoco shares in 1999 in order to free up capital for investment in other businesses.