Constellation Energy Group Inc. is Baltimore's sole Fortune 500 company, and everything it does, it does in a big way. It is one of the city's largest employers. One of the leading charitable donors. One of the most active corporations in civic life, from nonprofit boards to economic development efforts.
"They sponsor everything in town," says Aris Melissaratos, the secretary of the Maryland Department of Business & Economic Development.
In a city well accustomed to the loss of corporate headquarters, just the thought that Constellation might be sold to an out-of-state business sent shivers through the region yesterday.
"They certainly have a long reputation of deep commitment," said Peter V. Berns, executive director of the Maryland Association of Nonprofit Organizations, which is among the company's regular beneficiaries.
"There would ... be a lot of trepidation about any corporate change that might change that level of commitment."
Constellation is reportedly in merger talks with the parent of Florida Power & Light Co., but it was unclear yesterday what form any deal might take - including who would run the company and where.
Constellation declined to comment.
But Baltimore's history of getting the short end of the stick where mergers are concerned - particularly in the 1990s, when it lost one marquee financial institution after another - makes it easy for people to fear the worst.
The Maryland business community would be "losing a leader here," said Richard P. Clinch, director of economic research at the University of Baltimore's Jacob France Institute. "Maryland needs a strong business voice, and it hasn't generally had it in the last couple of years."
Constellation's local impact can be measured in time and money.
It donated $8.8 million in the Baltimore area last year, accounting for more than 80 percent of its total giving nationwide.
Constellation is consistently one of two contributors that give at least $2 million in employee and corporate dollars to the United Way of Central Maryland campaign, neck-in-neck with the Johns Hopkins Institutions.
It was the first company to come to the financial rescue of the B&O Railroad Museum when the nonprofit's roof collapsed during the 2003 blizzard.
Its annual Constellation Energy Classic golf tournament in Baltimore County, which puts a spotlight on the area, this year raised $830,000 for charities such as Special Olympics Maryland.
And its executives and managers sit on the boards of nearly 300 organizations in the region - including the Greater Baltimore Committee, which the company helped found 50 years ago when it was simply the Baltimore Gas & Electric Co.
"They have always been there ... for the city and for the region," said Donald C. Fry, president of the GBC, a business and civic leadership group. "They're always one of the first to step forward."
Local leaders were quick to point out that Constellation's legacy has not come to any definitive end. They tick down a litany of hope: A deal could work to Baltimore's advantage, and the city could end up with the headquarters of a much larger company.
Or, if the headquarters don't stay here, the merged company could keep its presence strong in a back-office town. Or negotiations could fall through.
"It's a story that's just starting to be told," said Betsy S. Nelson, executive director of the Association of Baltimore Area Grantmakers. "You truly don't know what will happen."
Some out-of-town companies are very active here; M&T Bank Corp., whose name is in lights on Ravens Stadium, is an oft-repeated example. But in general, a community loses ground when it loses a major headquarters.
Experts in philanthropy and business leadership say companies focus their time and money on their home towns - Constellation Energy is no oddity.
Even when businesses have the best intentions, nonprofits say, it's harder to get financing from the branch office of an out-of-state concern because the local vice presidents are several layers and hundreds of miles away from decision-makers. It's harder for civic efforts to get momentum because there are fewer movers and shakers to move and shake.
In the 1950s through the 1980s, "the business community was a driving force in Baltimore City politics and Baltimore City redevelopment," Clinch said. They don't have the influence they once did, he said.
"Will a branch manager be able to have the same clout in Annapolis as the chairman and president of a Fortune 500 company?" he said. "I don't think so."
He said that any economic blow to Baltimore, should Constellation be sold, would be less damaging now because the city is rebounding from business and job losses in the 1990s.
The downtown is redeveloping, city-based Under Armour Inc. just went public and many of Constellation's 6,500 employees in the state do local work that cannot easily be shipped to Florida, Clinch said.