Ventas, Chicago, and Cogdell Spencer, Charlotte, N.C., announced that the two real estate investment trusts had signed a definitive agreement for Ventas to buy Cogdell for $760 million to $770 million in cash, not including transaction costs.

The deal would give healthcare-focused Ventas ownership of an additional 72 medical office buildings, including two in development. The transaction is expected to close in the second quarter of 2012, subject to approval by Cogdell's shareholders and other closing conditions, according to a news release.

The transaction would not include Cogdell's design-build and development business, which is to be sold for a nominal amount to financial firm Lubar & Co., Milwaukee, before the Ventas deal is expected to close, but Cogdell can still seek other buyers of the design business for a 45-day period, according to the release.

Ventas this year already purchased healthcare REIT Nationwide Health Properties for $7.4 billion, creating largest healthcare REIT.

Listen to Debra Cafaro, chairwoman and CEO of Ventas, discuss business strategy and offer career tips in an August video interview after being named a Top 25 Women in Healthcare for 2011 by Modern Healthcare.