LTC Properties Inc. is raising $24.5 million through a private offering amid a big expansion by the health care real estate investment trust with a strategic partner. The Westlake Village-based REIT, which primarily owns nursing homes and medical offices, is selling 600,000 shares of common stock at $41.50 a share to RREEF America, a Chicago affiliate of RREEF Property Trust, according to a regulatory filing on Friday. The proceeds will be used to pay down existing debt, general corporate purchases and to fund acquisitions, development and other investments. The REIT also said it has purchased a 48-unit senior memory care facility in Castle Rock, Colo. for $9.8 million. It serves the greater Denver area and is managed under a 15-year master lease with Senior Lifestyle Corp., a Chicago-based owner and operator of senior housing. The patients are private pay, meaning they are not dependent on government programs such as Medicare. LTC said it plans to expand its relationship with Senior Lifestyle by adding 13 assisted living properties with 500 units to the master lease. These communities are currently co-leased to other operators, but the leases expire at the end of 2014. “This acquisition underscores LTC’s interest in the growing memory care market, as well as our continued focus on increasing private pay revenue, and reducing the average age of our portfolio,” said Chief Executive Wendy Simpson in a statement. Shares closed up 12 cents, or a fraction of a percent, to $41.73 on the New York Stock Exchange.