The glow of Internet riches isn’t just attracting associates away from firms. Now it’s top partners who are venturing out to become “”entrepreneurs.

On Dec. 2, Richard Fields, a partner at Swidler Berlin Shereff Friedmanwhose insurance coverage group brings the firm as much as $50 million ayear, left Swidler to launch a novel Internet start-up company a venture hehopes will permit legal claims against insurance companies to be freelytraded like stocks and bonds.