Digital Realty fell in premarket trading after it announced its buying a $3.5 billion stake in three data centers from asset manager Blackstone on Tuesday.

The Austin-based global data center firm will pay $1.2 billion in cash and $2.3 billion in shares for data centers in Northern Virginia, valued at $7.8 billion. The transaction is expected to be completed on Tuesday.

Digital Realty will purchase Blackstone's 80% interest in two 96-megawatt data centers in Manassas, Virginia, and a 50% interest in one 96-megawatt data center in Sterling, Virginia.

It was last trading down 3.7% before the market opened.

This is a breaking news story. Please refresh for updates.