George L. Chapman, the chairman, president, and chief executive officer since 1996 of Health Care REIT, Inc., today announced his retirement from the Toledo-based real estate investment trust, effective immediately.

The company said Thomas J. DeRosa, 56, a director of the company, is the new chief executive officer, replacing Mr. Chapman, 66, who said he is stepping down to focus on his health and personal and civic commitments.

Mr. Chapman will continue to serve as a senior advisor to the company. Jeffrey Donahue, who was the company’s lead independent director of the board, will become Health Care REIT’s board chairman.

The company, which acquires, plans, develops, and manages real estate properties in the healthcare field, including senior living communities, medical office buildings, inpatient and outpatient medical centers, and life science facilities, said the succession process for Mr. Chapman’s eventual retirement had been in the planning stages for more than a year.

Earlier this year, Mr. Chapman signed a new three-year contract to continue to guide the company.

But Health Care REIT said the plans for his retirement were accelerated when the CEO and chairman recently informed the board of his intentions to step down this spring.

Health Care REIT, which was founded in 1970 and in 2013 had revenues of $2.88 billion, added that it had created a new Management Committee made up of company executives to work with Mr. DeRosa to help oversee day-to-day operations.

Mr. DeRosa currently resides in Aspen, Colo., but is in the process of relocating to Toledo.

Mr. Donahue said that Mr. Chapman’s contributions to the company “have been immeasurable, leading us for 18 years and through a period of tremendous growth.

“Under George’s leadership, we have built a deep, seasoned senior management team and transformed HCN into a global leader in the health care real estate industry, with a sterling brand and a $25 billion portfolio of high-quality properties across the United States, Canada, and the United Kingdom. On behalf of the entire board, I thank George for all he has done. We wish him well and are pleased he will be remaining on as an advisor to the company.”

First Published April 14, 2014, 3:13 p.m.