Darwin Professional Underwriters Inc. posted second-quarter net income that more than quadrupled from the year ago period.

The Farmington, Conn.-based company reported net income of $3.4 million compared with $600,000 in the 2005 period.

Gross premium written jumped 58 percent in the quarter, with year-to-date premium of $118 million representing a 67 percent rise for the first six months of last year.

The combined ratio fell two points to 96.3 this quarter, which the company said was driven by decreases in both the loss ratio and expense ratio.

Also in the quarter the company completed its public offering of 6 million shares at $16 per share.

According to company Chief Executive Officer Stephen Sills, “As we said at the time of our offering, we believe there is ample opportunity in the specialty markets for a company with the right people, approach and execution.”

The company focuses on the professional liability insurance market and underwrites directors and officers and errors and omissions policies.