Investment bank Piper Jaffray Cos. (NYSE: PJC) agreed to purchase Seattle-Northwest Securities for $21 million.

The deal, announced late April 17, is expected to help Piper Jaffray expand its municipal debt business and strengthen its public finance services within the middle market.

Should the transaction receive approval by Seattle-Northwest's shareholders, it is expected to close in the second half of 2013.

Piper Jaffray chief executive Andrew Duff (pictured) stated that the acquisition signifies "a significant step forward” in developing a national franchise and noted that the two firms have minimal geographic business overlap.

Founded in 1970, Seattle-Northwest is a public finance firm in the Northwest region that specializes in underwriting municipal securities.

Piper Jaffray, headquartered in Minneapolis, announced the deal just as it released financial results for the quarter, which ended Mar. 31.

For the first quarter of 2013, net revenues from Piper Jaffray's continuing operations were $109.5 million, roughly 23 percent less than the $140.9 million it pulled in during the previous quarter, and about four percent less than the $113.4 million it generated a year ago during the first quarter of 2012.

Financial services industry Investment banking