Specialty Laboratories Inc. on Friday agreed to be acquired by AmeriPath Inc. for $13.25 per share in a deal worth nearly $314.7 million that will take the company private.

Under the terms of the deal, AmeriPath will acquire all outstanding common shares of Specialty, a Valencia-based provider of diagnostic testing, for $13.25 per share. This represents a 27 percent premium to the average trading price for Specialty shares during the last three months, the companies said in dual statements. With approximately 23.8 million shares outstanding, the deal values Specialty at about $314.7 million.

AmeriPath said it will finance the transaction through a combination of cash on hand and committed private financing arrangements.

The company’s majority shareholder, Specialty Family Limited Partnership, and related parties would own about 20 percent of the combined company, which will be privately held.

The transaction is expected to close in the first quarter of 2006, subject to customary conditions and shareholder approval. Specialty said the partnership agreed to vote in favor of the acquisition, but the merger also needs to be approved by a majority of the company’s other shareholders. Specialty’s and AmeriPath’s boards have already approved the merger.

Shares of Specialty Laboratories rose 1.6 percent to settle at $13.23 on Friday.