Health Care REIT said it entered into a definitive agreement to acquire Sunrise Senior Living, which will allow the Toledo, Ohio-based real-estate investment trust to capture more of the market driven by the demands of an aging population.

Health Care REIT said in a news release that the real estate value is about $1.9 billion. The company will pay about $950 million in cash for Sunrise; the balance will be paid through the assumption of debt, according to the release.

Sunrise Senior Living, based in McLean, Va., operates 20 wholly owned senior housing communities and has invested in joint ventures that own 105 senior housing communities.

Many of Sunrise's communities are located in affluent regions in metropolitan areas, according to statements made by Health Care REIT executives during a conference call.

The combined company will operate more than 58,000 units of senior housing in the U.S., Canada and the U.K.

During the call, Health Care REIT Chairman and CEO George Chapman said his company has reported “extraordinary growth” as a result of changes to the healthcare market in recent years.

“We expect the evolution of healthcare will continue, given the need for professional management, technology and economies of scale,” Chapman said during the call. “This will drive continuing change and consolidation, resulting in larger professionally managed branded operators in health systems that should further strengthen our portfolio valuation. Sunrise will be a key player in that evolution.”

The deal is expected to close in the first half of 2013.