Investment bank Piper Jaffray announced it has entered a definitive agreement to purchase Seattle-Northwest Securities in a transaction valued at approximately $21 million.

Founded in 1970, Seattle-Northwest is a public finance firm in the Northwest region. The firm is an established leader in underwriting municipal securities, and its sales and trading division distributes bonds nationwide.

Piper Jaffray and Seattle-Northwest have minimal geographic and business overlap, and the combination further strengthens Piper Jaffray’s public finance leadership in serving the middle market.

“This is a great combination for both firms,” said Andrew Duff, chairman and CEO of Piper Jaffray. “We have known and respected Seattle-Northwest for many years. A key part of our firm’s strategy is investing in our public finance business, and this represents a significant step forward in developing a national franchise for our business.”