A definitive agreement has been reached between Ameriprise Financial, Inc. and J. & W. Seligman & Co., Inc. under which the Minneapolis-based financial services firm would acquire the New York-based asset management firm for a total consideration of $440 million. The transaction is expected to be completed in the fourth quarter of this year.

Founded in 1864, privately-held Seligman manages an estimated $18 billion in assets in open- and closed-end funds, hedge funds, and institutional accounts. According to an announcement from Ameriprise, the Seligman fund will retain their management teams and brand names, but will now operate under the umbrella of RiverSource, Amerprise’s U.S. investment management division.