The Federal Reserve's $3 trillion balance sheet is not too big when compared to the entire banking system — at least, that's what Steve Schwarzman, CEO of Blackstone Group (BX), said.

As a result, he's not worried about the central bank's continued commitment to quantitative easing. 

"When the [financial] crisis started, the U.S. Fed was only about $800 billion," Schwarzman said in a "Squawk Box" interview. "Citibank was about four and a half times the size of our entire central bank. That seems a bit odd to me.

"The idea that the central bank is now at [about] $3 trillion and Citibank is down to around $2.4 trillion still doesn't seem like the central bank is massively scaled to the size of the U.S. banking system in toto," he added.