1816: Rembrandt Peale and four other prominent Baltimoreans form the country's first gas utility, Gas Light Co. of Baltimore.
1880: After fierce competition, Gas Light Co. merges with two rivals to form Consolidated Gas Co. of Baltimore City.
1906: Consolidated Gas merges with two electric utilities to form Consolidated Gas Electric Light and Power Co.
1955: Deciding that the name it has used for half a century is "too long-winded," Consolidated is renamed Baltimore Gas and Electric Co.
1982: The company seeks to create a holding company called BGE Corp. This, the company tells shareholders, would give "management greater flexibility to develop alternative business opportunities."
1985: After the holding company plan is blocked by state regulators, BGE creates a subsidiary, Constellation Holdings.
1992: Congress passes the Energy Policy Act, setting the stage for deregulation of the electric utility industry.
1995: BGE and Potomac Electric Power Co. announce merger plans. Two years later, the deal is killed. BGE and Pepco blame regulatory constraints.
1998: BGE and Goldman Sachs & Co. form a joint venture, Orion Power Holdings Inc. Orion buys a number of power plants from various companies before being sold in 2002 for $4.8 billion to Houston-based Reliant Resources Inc.
1999: Constellation Energy Group Inc. becomes the holding company for BGE and related companies. Maryland passes an energy deregulation law.
2000: Constellation announces plan to split into two companies, BGE and a company to generate and sell power nationally.
2001: Constellation junks its plan to split. At the same time, it announces that Mayo A. Shattuck III, former chairman of Deutsche Banc Alex. Brown Inc., will become its chief executive officer. Christian H. Poindexter, who had led the company, retires.
2002: The company reduces its work force by 10 percent, reorganizes its management and closes its BGE Home retail stores.
November 2005: Constellation and investment partners outline a $4 billion bid to buy the owner of Europe's largest coal-fired power plant, Drax Group Ltd. Drax shareholders reject the deal.
Dec. 2005: Constellation announces merger with FPL Group Inc. Oct. 2006: Constellation and FPL scrap merger plans amid Maryland political fight over deregulation and higher electricity rates.
Sept. 17, 2008: Constellation says it is in active discussions with "potential strategic partners" for a possible sale of the company. Its shares fall by double digits for the third straight day.