TIAA-CREF has announced plans to acquire Nuveen Investments for $6.25 billion, including debt. TIAA-CREF believes the acquisition “significantly expands” the products and services it provides, according to a press release.

Nuveen, a diversified investment management company, has roughly $221 billion in assets under management. It will operate as a separate subsidiary within TIAA-CREF’s asset management business, retaining its current multi-boutique business model and continuing to support its investment affiliates through scaled distribution, marketing and administrative services.

The addition of Nuveen brings TIAA-CREF’s total assets under management to about $800 billion. In addition, TIAA-CREF says the transaction also adds diversification to the firm’s “investment and distribution platform while bolstering its award-winning mutual fund offerings.”

TIAA-CREF is acquiring Nuveen from an investor group led by Madison Dearborn Partners, a private equity investment firm. “The acquisition of Nuveen can generate greater returns that will benefit our customers,” said Roger W. Ferguson Jr., TIAA-CREF’s president and CEO, in a statement. “This transaction reinforces our position as a leading diversified financial services organization with a broad mix of product offerings to serve clients today and those in retirement for decades to come.”

John Amboian will remain the chief executive officer of Nuveen, and Nuveen’s current leadership and key investment team will stay in place.