TSM specializes in the engineering and power business.

ProSight spokesman Darryl Siry says the company, started in 2009, takes an “opportunistic approach” to providing very specialized coverage to niche markets where it has differentiated underwriting and claims expertise.

The mindset extends to the company's distributors. It only uses a limited amount of distributors for specific risks. For example, ProSight uses just two managing general agents for attorneys' professional liability—one for smaller firms and one for large firms, says Siry.

Also this week, ProSight announces a partnership with program-administrator Tangram Insurance Services for its non-profit workers' compensation program.

ProSight Specialty Insurance focuses on niche markets where it has differentiated underwriting and claims expertise and partners exclusively with specialist distributors who have a deep understanding of their customers.

Last November ProSight completed the acquisition of NYMagic Inc., an insurance holding company whose property and casualty insurance subsidiaries specialized in underwriting ocean marine, inland marine and non-marine liability insurance.

The ProSight group is comprised of New York Marine & General Insurance Co., Gotham Insurance Co. and Southwest Marine & General Insurance Co.

About 33 percent of the group's direct written premiums in 2010 are in ocean marine, according to Highline Data, a part of Summit Business Media. More than 21.5 percent of direct premiums are written in New York. The group posted net income of $22.4 million in 2010.

ProSight Specialty Insurance is backed by affiliates TPG Capital and GS Capital Partners.