The Carlyle Group is selling a majority stake in the Nature’s Bounty Co. to investment company KKR, Carlyle announced Monday.

The sale is expected to close by the end of this year. Carlyle said in a statement it will retain “a significant stake” in the Ronkonkoma-based vitamin and food supplement maker. Financial terms of the deal were not disclosed.

The Long Island company’s brands include Nature’s Bounty, Sundown Naturals, Solgar, Osteo Bi-Flex, MET-Rx, Pure Protein, Body Fortress and Puritan’s Pride.

Asked whether the acquisition would have any effect on Nature’s Bounty’s staffing levels or its headquarters on Long Island, a spokeswoman for KKR said, “At this early stage we don’t have any additional comment beyond this morning’s press release.”

Steve Cahillane, president and chief executive of Nature’s Bounty, said in a statement yesterday that the company has “spent substantial time and effort over the years improving our business. . . . This work has laid the foundation for our continued growth, and that is part of the value and opportunity that KKR sees in us. The same is true for Carlyle, who decided to maintain a significant stake in the company.”

Nature’s Bounty has about 2,100 employees on LI and about 11,000 globally, the spokeswoman said.

advertisement | advertise on newsday

KKR, headquartered in Manhattan, is an international firm with investments in private equity, energy, infrastructure, real estate, credit and hedge funds.

Washington, D.C.-based Carlyle is an international alternative asset manager with $162 billion in assets. It purchased Nature’s Bounty, formerly named NBTY, in 2010 for $3.8 billion.

Last month, Nature’s Bounty announced it would sell its United Kingdom health and wellness retail chain, Holland & Barrett International, for more than $2.25 billion to an investment firm controlled by Russian billionaire Mikhail Fridman.

Separately yesterday, KKR said it is buying health information website WebMD in a deal valued at about $2.8 billion.

KKR’s Internet Brands subsidiary, an online media and software services provider, will pay $66.50 per WebMD share. That’s an approximately 20 percent premium to the New York company’s Friday closing price of $55.19.

With AP