June 7 (Reuters) - Investment firm Blackstone Group Inc will buy data center operator QTS Realty Trust Inc for about $6.7 billion, the Wall Street Journal reported on Monday.

The buyout firm's infrastructure unit along with its non-traded real-estate investment trust will pay $78 per share for QTS, according to the report.(https://bit.ly/3ioXRxx)

The price represents a premium of about 21% to QTS' closing price on Friday.

A COVID-19 pandemic-led remote working environment boosted demand for cloud services, which are reliant on data centers. QTS has more than 7 million square feet of data center space throughout North America and Europe.

The transaction is valued at about $10 billion, including the assumption of the data center operator's existing debt, the report said.

Blackstone and QTS did not immediately respond to Reuters' request for comment.

(Reporting by Chavi Mehta in Bengaluru; Editing by Amy Caren Daniel)