Medical malpractice insurance provider SCPIE Holdings Inc. said Tuesday it has agreed to be bought by The Doctors Company, a physician-owned competitor, for about $268.8 million.

Napa-based Doctors wants to buy Los Angeles-based SCPIE for $28 per share in cash, which represents a 27 percent premium from the company’s closing price on Monday. SCPIE valued the deal at $281 million, based on 9.6 million shares outstanding.

As a result of the deal, privately-held Doctors would expand its market in California to nearly 19,000 physicians and become the nation’s largest insurer of physician and surgeon professional liability insurance.

SCPIE did not announce a date for a shareholder vote on the acquisition. Both companies were founded by physicians in 1976.

Shares of SCPIE jumped $5.06, or 23 percent, $27.15 in midday trading.