Blackstone Group LP cemented its position as the world’s biggest private-equity investor in real estate with a global buying spree that includes General Electric Co. assets and a California-based shopping-center owner.

The agreement to buy GE real estate assets valued at $23 billion in a joint deal with Wells Fargo & Co. is the largest real estate transaction since the financial crisis and among the biggest for New York-based Blackstone, whose purchases include the record $39 billion acquisition of Equity Office Properties Trust in 2007 and the $26 billion takeover of Hilton Worldwide Inc. the same year.