Berkshire Unit to Acquire Another Malpractice Firm

Berkshire Hathaway’s malpractice insurance unit is acquiring the Princeton Insurance Company to expand its business.

Medical Protective Company, which is owned by Warren Buffett’s Berkshire, announced the deal Wednesday. Medical Protective is buying Princeton from Medical Liability Mutual Insurance Company.

Terms of the all-cash deal were not disclosed, but the transaction is expected to close before the end of 2011.

Princeton Insurance is based in Princeton, N.J. and employs about 100 people. It writes professional liability policies that generate about $140 million in premiums annually.

Buffett says this add-on deal will allow Medical Protective to expand its business and provide a stable insurer for Princeton’s customers.

Medical Protective is one of about 80 different companies owned by Omaha-based Berkshire Hathaway.