RONKONKOMA, N.Y. — Nutritional supplements maker NBTY Inc. has agreed to be acquired by the Carlyle Group for $3.8 billion. The company expects the deal to close by the end of 2010.

Nutritional supplements maker NBTY Inc. has agreed to be acquired by the Carlyle Group for $3.8 billion. The company expects the deal to close by the end of 2010.

Under the terms of the agreement, Carlyle will acquire all of the outstanding common shares of NBTY for $55 per share in cash, which represents a premium of approximately 57% over the average closing price of NBTY shares during the 30 days ended July 14.

The deal was unanimously approved by the NBTY board of directors, which has recommended that stockholders approve the transaction.

Completion of the acquisition is subject to customary closing conditions, including approval by NBTY shareholders and regulatory approvals, but is not subject to any financing conditions.

"This transaction delivers exceptional value to our shareholders," said Scott Rudolph, NBTY chairman and chief executive officer, in a statement. "For our wholesale and retail customers, our commitment to quality and innovation will continue to be our focus. We will leverage Carlyle’s global resources and consumer sector knowledge to further drive the company’s global growth."