Powerful health care real estate investment trust Ventas says it has agreed to acquire Chicago-based Lillibridge Healthcare Services in a deal valued at up to $400 million. The transaction, easily one of the largest recent deals in the medical real estate realm, is scheduled for completion in the third quarter.

With the acquisition, Ventas will gain 100% interest in Lillibridge, a medical real estate company, and real estate interests in 95 medical office buildings and ambulatory facilities across the country. Lillibridge owns, develops and manages medical office buildings for not-for-profit health care systems.

Ventas Chairman and CEO Debra Cafaro called the deal a breakthrough for the REIT with regard to its strategy of becoming a leader in the medical office building and ambulatory facilities sector, a $173 billion market that is expected to grow by more than 30% in coming years. Ventas currently owns a portfolio of health care and seniors housing assets.

“The combination of our balance sheet and access to capital with Lillibridge’s leading operating platform offers a compelling solution for hospitals as they expand, consolidate and evolve to meet increasing demand for medical care,” says Cafaro.

Aging baby boomers will drive demand for health care services in coming years, creating fresh opportunities for the development and financing of outpatient medical services, according to Ventas.

With the acquisition, Ventas will manage or own 154 medical office buildings covering 8.4 million sq. ft. in 20 states and the District of Columbia. It will operate its medical office business under the Lillibridge name. Todd Lillibridge, founder of Lillibridge Healthcare Services, has been named executive vice president of medical properties at Ventas.

“In combining with Ventas, we have uniquely positioned the company to support our hospital and health system clients as they continue to grow and serve their patients amidst an uncertain reimbursement and capital market environment,” says Lillibridge.

Ventas has a portfolio of more than 500 properties in 43 states and two Canadian provinces. The properties include more than 200 seniors housing communities, as well as skilled nursing facilities, 40 hospitals, and medical office buildings.

Ventas expects to fund the new transaction with a combination of cash on hand, borrowings under its revolving credit facilities and assumed secured mortgage financing. Goldman, Sachs and Co. is acting as Ventas’ lead financial advisor and Barclays Capital is also advising. Barack Ferrazzano Kirschbaum & Nagelberg LLP is serving as its legal counsel.