Guinness plc was at the center of the 1986 Guinness share-trading scandal.
The scandal arose during Guinness's successful takeover bid for the Distillers Company, a major drinks business. Guinness executives and associates were accused of arranging improper support for Guinness shares, helping maintain or increase the share price while the takeover was being pursued.
The investigation led to criminal convictions and civil proceedings involving several prominent business figures. Guinness chairman Ernest Saunders was among those convicted, although his conviction was later overturned after medical evidence concerning his treatment was reconsidered. The affair damaged confidence in UK corporate governance and takeover practices.
The company is often confused with Distillers because Distillers was the target of the takeover. Guinness plc was the bidder and the company whose share dealings formed the core of the scandal. Guinness later became part of the drinks group Diageo, created in 1997 through the merger of Grand Metropolitan and Guinness.