Oct 25 (Reuters) - Blackstone Group Inc said on Monday that it had agreed to buy Simply Self Storage from Canada's Brookfield Asset Management Inc for about $1.2 billion.

Brookfield acquired Simply Self Storage for $830 million in 2016 and the company has a portfolio of 8 million square feet of self-storage facilities.

Blackstone said Simply Self Storage is one of the top five private owners of self-storage in the United States, and the deal would make its real-estate investment trust, BREIT, the third biggest non-listed owner of such facilities.

"Self-storage is a resilient sector through economic cycles because of low tenant turnover, minimal maintenance costs and stable cash flows," BREIT Chief Executive Officer Frank Cohen said.

The deal is expected to close before the end of 2020.

BREIT was launched in 2017 and has a net asset value of $19 billion. (Reporting by Kanishka Singh and Ankit Ajmera in Bengaluru; Editing by Aditya Soni and Anil D'Silva)