RONKONKOMA, N.Y. — Dietary supplements supplier NBTY Inc. has agreed to be purchased by private equity firm Carlyle Group for $3.8 billion in one of the biggest private equity deals thus far in 2010.

Carlyle’s $55 a share cash offer is 47% above NBTY’s stock close on Wednesday.
NBTY announced the deal a day after reports emerged that the company was being pursued by both Carlyle and rival private equity firm Blackstone Group LP.

NBTY, supplier of supplement brands including Nature’s Bounty, Osteo Bi Flex, Sundown, MET-Rx, Ester C and Pure Protein, expects the deal to close by year end.

"This transaction delivers exceptional value to our shareholders," said NBTY chairman and chief executive officer Scott Rudolph. "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."

Sandra Horbach, Carlyle managing director and head of its consumer and retail sector team, said, "NBTY is an outstanding business with well-established brands, a proven vertically integrated multichannel/multi-geography strategy and strong, long-standing customer relationships. We are impressed with the business that has been built under the leadership of Scott Rudolph, and are excited to work with him and the senior management team to drive continued growth."

NBTY’s latest quarterly profit fell well short of Wall Street’s expectations, as a boost in TV advertising cut into the bottom line.