The deal follows a spate of acquisitions in the seniors' housing and assisted living space as companies rush to deploy the cash pile they were sitting on during the downturn.
Nearly 40 million people, or 12.9 percent of the U.S. population, were older than 65 years in 2009 -- a number expected to grow to 19 percent by 2030, according to the Department of Health & Human Services.
HCP is to pay $3.53 billion in cash, $1.72 billion reinvested from the payoff of HCP's existing debt investments in HCR ManorCare, and $852 million in HCP common stock issued directly to HCR shareholders.
The Healthcare REIT also has an option to buy a 9.9 percent stake in HCR ManorCare for an additional price of $95 million, the company said.
HCP said it has obtained a commitment for a bridge loan of up to $3.3 billion.
HCP also said it intends to issue debt and equity in place of any borrowings available under the bridge loan.
The sale leaves Carlyle and ManorCare's management remaining as owners of the operating company.
Carlyle bought ManorCare in 2007 in a $4.9 billion deal. The deal was controversial at the time, drawing ire from the SEIU union which had taken aim at the private equity industry's corporate takeover wave, on concerns about job cuts and workers' benefits.
The SEIU also said in 2007 the ManorCare deal would negatively impact the care of patients - which was refuted at the time by Carlyle.
Under the deal announced on Monday, HCP will buy 338 nursing and assisted living facilities in 30 states, with the highest concentrations in Ohio, Pennsylvania, Florida, Illinois and Michigan. HCR ManorCare will continue to operate the assets.
HCP said it expects the deal to close late in the first quarter of 2011.
This sale provides stability and predictability to the company's operations, enabling them to focus exclusively on high quality skilled nursing and rehabilitation services, Carlyle spokesman Chris Ullman said in an e-mailed statement. HCR Manor Care is well-managed and positioned for continued growth.
Carlyle has been on a deal tear recently.
In July, it announced a $3.8 billion deal to buy U.S. nutritional supplements maker NBTY Inc. In October it struck a $2.9 billion deal to buy communications cable maker CommScope Inc
The private equity firm, which on Monday lost its CFO Peter Nachtwey to asset manager Legg Mason, is also preparing for a potential IPO, a source familiar with the matter previously told Reuters.
CSCA Capital Advisors, Citi, UBS and Wells Fargo were as financial advisors to HCP. JPMorgan advised HCR ManorCare.
(Reporting by Steve James and Abhinav Sharma; Editing by Richard Chang and Anshuman Daga)