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May 1 (Reuters) - U.S. real estate investment trust Duke Realty Corp said on Monday it would sell its medical office building assets to Healthcare Trust of America Inc , an owner and operator of medical offices, for $2.8 billion in cash.

The deal, which also include Duke Realty's medical office operating and development platform, will give HTA access to 78 properties.

Reuters reported in March that Duke Realty was exploring the sale of its medical office buildings, as it seeks to focus on its warehouse portfolio.

As part of the deal, Duke Realty will provide seller financing of $330 million to HTA.

The acquisition is expected to close in stages through the second and third quarters of 2017, Duke Realty said.

Morgan Stanley was Duke Realty's financial adviser, while Wells Fargo's Eastdil Secured unit advised HTA. (Reporting by Divya Grover in Bengaluru; Editing by Sai Sachin Ravikumar)