Ventas Inc., one of the nation’s top healthcare real estate investment trusts, has agreed to acquire Provident Senior Living Trust, an unlisted senior living real estate investment trust, for $1.2 billion, Ventas said Tuesday.

“The transaction expands our portfolio and substantially advances our strategic goals of increasing our private-pay revenue sources and increasing our tenant diversification by adding 68 high-quality, private-pay independent and assisted living assets to our portfolio,” said Debra A. Cafaro, the chairman, president and CEO of Ventas.

Ventas, whose primary tenant is Kindred Healthcare Inc., a major skilled nursing chain, expects that, upon the closing of the acquisition, over one-third of its total revenues will be derived from private-pay independent and assisted living facilities, on an annualized basis. It expects the transition to close in the second quarter of this year.

Provident’s 68 independent and assisted living properties are in 19 states.