Sunrise Senior Living (SRZ) has agreed to be acquired by Health Care REIT (HCN) in an all-cash transaction valued at just under $845 million.

The deal brings Health Care REIT's senior housing units to about 58,000, making it one of the world's biggest operators of assisted-living units.

The $14.50 a share offer represents a premium of 62.4% to Sunrise Senior Living’s closing price on Tuesday. The companies said the purchase price reflects a real estate value of about $1.9 billion.

Shares of Sunrise jumped about 60% to a multi-year high of $14.26 on the news. The McLean, Va.-based retirement home operator's board has unanimously approved of the deal.

As part of the agreement, which is subject to regulatory approvals and slated to close in the first half of 2013, Health Care REIT will acquire 20 wholly-owned senior housing communities operated by Sunrise in the U.S. and Canada. It will also get Sunrise's joint ventures, adding up to about 105 senior housing communities.

"This acquisition powerfully advances our strategic vision: own the highest quality, private pay seniors housing communities in strong, growing, affluent markets and align with experienced, dynamic management teams,” Health Care REIT Chief Executive Officer George Chapman said in a statement. 

The real estate trust typically buys healthcare-related properties including assisted-living and retirement communities, as well as nursing facilities and hospitals.

Follow Jennifer Booton on Twitter at @Jbooton