Independent real estate investors had mixed views on whether rates of returns in the teens were needed to attract investors to what they called perhaps the most desirable piece of undeveloped property in the city.

Allan Riorda, a principal in Columbia with Lee and Associates, a national commercial real estate firm, said he's seeing returns of 6 percent to 9 percent on properties. He deemed 14 percent a "pretty good return" for a development as desirable as Harbor Point.

"I don't think it needs to be as high as 14 or 15 percent," he said. "That's great real estate, and everything's been moving toward the water. That's a higher-end development that would attract larger institutional investors. There's risk, but I wouldn't deem it as substantial a risk as building in a different location of Baltimore."

But Steven McCraney, a 20-year industrial real estate developer based in Florida, said the proposed rates of return were consistent with current market rates for deals of that size.

"I know what the public is thinking: How could somebody make so much money?" he said. "But the truth of the matter is: The numbers make sense. They're market-driven numbers. To attract that kind of capital, if they're not getting that kind of return, I don't think they're going to be interested. Nobody's stepping to the plate for 9 percent. Not happening."

Mayor Stephanie Rawlings-Blake has said the Harbor Point project would create about 7,200 construction jobs and that roughly 9,200 jobs would be supported by the businesses that move in.

The former site of the Allied Signal chromium plant, Harbor Point now sits mostly vacant. The developer plans to start work this summer on a 23-story skyscraper to house the Exelon headquarters, space the company would lease from Beatty for about $120 million over 15 to 20 years. The tower would be the first phase of the project.

The information about the development's rate of return and potential profit was included in a supplemental report written June 14 by city consultant Municap Inc., a Columbia-based public finance consulting firm.

McKenzie and Doan said developments are different and that rates of returns vary widely based on the scale, timing and risk of a project.

"I'm sure Michael would like to see a higher rate of return," Doan said. "There's incredible risks involved."

Baltimore Sun reporter Scott Calvert contributed to this article.