Earnings of brokerage Piper Jaffray Companies doubled in the fourth quarter on the strength of sharply higher revenue.

The Minneapolis-based company reported adjusted fourth-quarter earnings of $1.91 per share. Revenue increased 33 percent to $187.6 million. Net earnings were $1.70 per share.

"We finished the year very strong, generating sequential improvement across all areas of the company," CEO Andrew Duff said in a statement. "As a result, we produced our best quarterly revenue since we went public in 2004. Our equity and asset management businesses led the way, supported by our fixed income activities, which rebounded from difficult market conditions in midyear."

Piper Jaffray had $11.2 billion assets under management at year end, compared with $9.1 billion a year ago. During 2013, the company repurchased 1.72 million shares of its stock, or 11 percent of the shares outstanding, at a price of $55.9 million.

Piper Jaffray shares rose 3.2 percent Wednesday.