Credit card lender MBNA will sell its offices in Rockland and Camden, an apartment complex in Belfast, a mountainside corporate retreat in Northport and other midcoast real estate to a Baltimore-based developer with ties to Maine, the company announced Wednesday.

Terms were not disclosed. The properties in Knox and Waldo counties are assessed for a combined $50 million.

The deal includes the 76,464-square-foot harbor-front complex in Rockland, where MBNA has been the city’s biggest taxpayer, and the Knox Mill on Megunticook River in Camden, where MBNA began its Maine operations with 75 employees in 1992.

The company, which employs about 3,000 people in seven locations around the state, has been downsizing its work force in Maine and elsewhere. In the past year, it has offered more than 7,000 of its 28,000 employees worldwide retirement or voluntary severance packages.

The company said Wednesday it has signed a sales-and-purchase agreement with newly incorporated Maine Investment Properties LLC of Baltimore.

Maine Investment Properties’ vice president for business development is Brett Cohen, son of Bangor-area real estate developer Donald Cohen.

The key properties MBNA is selling are:

. Its harbor-front and Old County Road offices and former Courier Publications building at 1 Park Drive, all in Rockland. The harbor-front complex is situated on 10 acres and includes 1,860 feet of Rockland Harbor frontage. It is assessed at $17.7 million.

. The Knox Mill complex in Camden, assessed at about $7 million.

. The Point Lookout corporate retreat center in Northport, assessed at about $15 million.

. The 48-unit Springbrook Hill apartment complex off Route 3 in Belfast, built in 2001, assessed at approximately $11 million.

Maine Investment Properties was incorporated in April to undertake the acquisition, Brett Cohen said Wednesday. He would not say when the purchase of the MBNA properties will close.

The company is affiliated with WJS&A Inc., also of Baltimore, a real estate investment firm that incorporated in 1987. That company’s principal owner is Walter J. Skayhan III.

Cohen would not discuss the connections between Maine Investment Properties and WJS&A. He said Maine Investment Properties has three principals but wouldn’t identify them.

“We’re local real estate developers,” Cohen said, with experience in residential, multifamily and commercial development. He wouldn’t discuss specific development projects.

“The principals in the deal have over 25 years of real estate development experience,” Cohen said.

Bob Hastings, director of the Rockland-Thomaston Area Chamber of Commerce, believes a new owner actively engaged in developing or marketing the properties is good news.

“We don’t know who they are yet,” he said of Maine Investment Properties. The Chamber “always had a marvelous relationship with MBNA,” he said, and he hopes that will be the case with the new owner.

“Our intent is to help move this property,” Hastings said.

He described the Rockland waterfront office, the Knox Mill in Camden and the Northport retreat center as “premier sites, which will probably attract premier tenants.”

The waterfront building could become an office for a major corporation or a hotel, Hastings said, while the Northport property could be turned into a large-scale conference center.

“It can go in a lot of different ways,” he said.

Hastings and Camden-Rockport-Lincolnville Chamber of Commerce director Andy McPherson expect to work closely with the Baltimore developer.

“I know nothing about these people,” McPherson said, but he hopes to be enlisted to help develop or market the local properties.

Cohen said his firm would honor existing leases for businesses that have moved into the Knox Mill in Camden and the building at 1 Park Drive in Rockland.

But Hastings and McPherson wondered about the long-term status of those tenants. The Rockland-Thomaston Chamber recently moved to the 1 Park Drive building, leasing from the city of Rockland, which in turn holds a long-term lease with MBNA, with an option to purchase the building.

McPherson said business tenants in the Knox Mill have five-year leases. A cinematographer with Maine ties has been negotiating to locate a film and video production facility inside the Knox Mill.

A Baltimore commercial real estate agent, a Maryland business journalist and a Baltimore lawyer who specializes in commercial real estate had not heard of Skayhan or Cohen.

Cohen said he was born in Portland but reared in Newburgh. He graduated from Hampden Academy in 1990.

He has the same title, vice president of business development, with WJS@A Inc. His Web site biography notes that Cohen graduated from the Wharton School of Business at the University of Pennsylvania, is a certified public accountant and worked for The Walt Disney Co. in a finance capacity.

The sale is likely to revive persistent rumors that MBNA is leaving Maine.

MBNA spokeswoman Carolyn Marsh has insisted over the last year the company is committed to its Maine operations.

It now employs 1,900 who work in the company’s Belfast headquarters and 1,100 who work in telemarketing centers in Fort Kent, Presque Isle, Farmington, Orono, Brunswick and Portland.

But the company is not cutting back because of poor earnings: MBNA’s after-tax profits in 2004 were $2.7 billion, up 15 percent over the previous year.