Developer and banker Edwin F. Hale Sr. is asking a Baltimore court to stop Constellation Energy, the parent of Baltimore Gas and Electric Co., from shutting off the lights of First Mariner Tower and 15 tenants occupying the Canton Crossing building.

It is the latest challenge for Hale, whose First Mariner Bancorp has suffered in the past two years after making bad mortgage loans at the height of the housing bubble. Baltimore's largest independent bank reported a $2.4 million loss in the three months that ended June 30. Hale has said he wants to raise capital to shore up the company's finances.

Hale's request is part of a lawsuit against Constellation Energy Group over a dispute involving a utility distribution plant that transmits power to the First Mariner Tower, where the bank has its headquarters.

Hale had entered into a 2005 contract in which a Constellation affiliate agreed to build and operate the plant while he would own it, according to the lawsuit filed July 17 in Baltimore City Circuit Court. Hale accuses Constellation of misrepresenting the benefits of owning the plant, which switched to Constellation ownership in 2007 after the deal was restructured.

In July, Constellation sent a "default" letter to Hale for failing to pay $493,407 in consumption and maintenance charges related to the plant.

The default could prompt Constellation to shut down the plant and cut off power to Hale's building and tenants including CareFirst BlueCross BlueShield, Comcast and testing service firm Prometric, according to the lawsuit.

"An interruption in electric power would cause irreparable harm to those tenants and the members of the public they serve," the lawsuit said.

Hale could not be reached for comment Friday.

Constellation spokesman Rob Gould declined to comment on the default letter. But Gould said Constellation "strongly disputes and denies the allegations" in the lawsuit, which also seeks $60 million in damages.

The company on Friday filed a motion asking the court to dismiss Hale's lawsuit, noting a 2008 forbearance agreement between the two parties.

"Constellation Energy has a clear track record of having worked cooperatively with all of the parties involved in the Canton Crossing project," Gould said, noting that the company has restructured the deal with Hale several times to address his financial problems, including the 2007 ownership change.

"We feel absolutely comfortable that we've not violated a single federal or state regulation or law governing our interactions with the plaintiffs and have met all of our obligations under the agreements."