Seattle-based Columbia Pacific Management and the affiliated alternative investment firm Columbia Pacific Advisors have acquired a senior housing operator in India and said they plan to significantly expand their portfolio in that country over the next five years.

The actions, according to Columbia Pacific, are spurred by the speed of growth of the senior population in India, which already totals 100 million, and an emerging middle class there.

Serene Senior Care, the acquired company, has 735 residential units in four senior housing communities in South India and plans to have 1,700 units under management by this fall, according to Columbia Pacific. Columbia Pacific Management said it plans to more than quintuple the number of the units Serene Senior Care has under management, to 5,000 units within five years. Two new communities are planned for Bangalore.

“Columbia Pacific Management has been operating hospitals in India for more than a decade, and we are one of the most experienced operators of senior housing both in the U.S. and China,” said Matthew Powell, development director for Columbia Pacific Management.

Columbia Pacific Advisors said it has built an acquisition and development pipeline that consists of more than 3,300 senior housing units, more than 1,200 multifamily units and more than 1.2 million square feet of commercial space around the United States.

Columbia Pacific Management’s hospital companies operate 28 hospitals and three clinics across India, China, Malaysia, Vietnam, Indonesia and Kenya under the brands Columbia Asia, Columbia China and Columbia Africa. Columbia Asia, which operates hospitals in India, Malaysia and Indonesia, opened its first hospital in India in 2005 and now has 11 multispecialty hospitals in India, the company said.

In 2011, Columbia Pacific Management received government approval to open the first foreign-owned, for-profit senior care facility in China, according to the company. The company said it now owns and operates three senior care facilities there — two in Shanghai and one in Beijing — with a pipeline of additional communities under development.