Mayor Stephanie Rawlings-Blake said she met Wednesday with Constellation Chairman, President and CEO Mayo A. Shattuck III, who assured her the deal would mean more jobs and a new office building for Baltimore and that the company’s philanthropy in the region would not go away.

“He’s committed to making sure that this is not just a win for Constellation, but a win for Baltimore city. I’m proud of the work that he did on that and I’m looking forward to having them be a part of our family,” the mayor said.

While the city is losing a Fortune 500 company, Rawlings-Blake said the deal was “a net job gain for the city.”

“It’s laying the foundation for further job growth in the city,” the mayor said. “I think you can have the glass half full or the glass half empty. I look at it half full and keep moving.”

The companies said the investment in the state includes more than $50 million to develop 25 megawatts of renewable energy in Maryland.

Gov. Martin O’Malley said the proposed merger is subject to approval by the state’s Public Service Commission,

“We will participate actively in those proceedings to ensure that the transaction is in the best interest of Maryland ratepayers,” O’Malley said in a statement.

Constellation has had a rocky history with the governor and state regulators.

O’Malley used rising electricity rates following deregulation as a key part of his first campaign for governor. State lawmakers approved deregulation in 1999 and rates began to rise as O’Malley sought office when caps began to be lifted. After the governor took office, Constellation and the state battled in court over rising rates before reaching a $2 billion settlement.

The deal also marks the third attempt at a merger in the past few years by Constellation.

Uncertainty over rate regulation led Constellation to drop a proposed merger with Florida Power & Light in 2006. In 2008, a deal with Warren Buffett’s MidAmerican Energy prompted by the credit crisis was eventually terminated. And Constellation has also exited a subsequent joint nuclear venture with Electricite de France.

Shattuck said the two sides feel the deal will be well received, noting differences in the industry now and when Constellation tried to merge with Florida Power & Light.

“We’re in a different environment than we were in six years ago when hurricanes and the lifting of the rate caps and other factors made the contemplation of a merger much different than it is today,” Shattuck said.

The CEO noted BGE, which serves 1.2 million electric customers and 630,000 gas customers, recently announced electric rates are expected to drop 11 percent and added the two sides tried to be sensitive to the interests of all stakeholders, Shattuck said.

“So, what we tried to do this time, which is clearly different from six years ago, is that a lot of the contemplation of this merger has been thinking about how to make this in the best interests of this organization, of the people, of our customers, of the state of Maryland, of the city of Baltimore,” Shattuck said.

Christian Johansson, who heads the Maryland Department of Business and Economic Development, said the agency intends to work closely with both companies to understand what the effect will be on jobs in the state. Johansson said the state intends to aggressively make the case that Maryland remains one of the best places for the companies to operate and do business.

“We’re reaching out at all levels to make sure that as they are making their decisions the state is advocating strongly for Maryland,” he said.