NEW YORK, JUNE 21 -- Kohlberg Kravis Roberts & Co. said today that it plans to recapitalize RJR Nabisco Inc., an indication the giant company will not be broken up and eventually will return to public ownership.

Under the plan, Kohlberg Kravis will retire a large part of the $6 billion in junk bonds it used to buy the food and tobacco company in a record $24.53 billion buyout last year.

Kohlberg Kravis also would issue preferred stock convertible into common stock in RJR Nabisco.

By retiring some of its junk bonds, which have fallen in value during recent months, Kohlberg Kravis would avoid having to pay a sharply higher interest rate on some of the securities next year.

The sale of stock under the plan also would counter any notions that Kohlberg Kravis plans to dismantle RJR Nabisco, as it did after it bought the consumer-products conglomerate Beatrice Co. in 1985.

Like Beatrice, RJR Nabisco has a variety of food lines and a separate tobacco business, but analysts say that while Beatrice was ripe for an unbundling of its disparate businesses, RJR Nabisco is not.

Beatrice ''had this and that -- a lot of things that didn't make sense to have together anyway,'' said Jack Maxwell, an analyst who follows RJR for Wheat, First Securities Inc. in Richmond.

RJR Nabisco has product lines that conceivably could be pared, but Maxwell said he doubted Kohlberg Kravis would begin unloading food divisions, and ''you can't sell bits and pieces of the tobacco business very well.''

Since its buyout, RJR has divested $5.66 billion in assets to pare its debt load, which now stands at $22 billion. Its Del Monte canned foods and fresh fruit businesses and some of its foreign holdings were among those sold.

RJR Nabisco said today that Kohlberg Kravis would invest an additional $1.7 billion in the company as part of the recapitalization, another move that points away from a breakup of the company. Analysts see RJR Nabisco returning to public ownership, beginning in the next few years.

RJR Nabisco said it was negotiating new loans with banks as part of the recapitalization plan. The company said it expected to begin enacting the plan by the end of July.

The recapitalization is intended to take off the market some of RJR Nabisco's junk bonds that have declined in value during recent months. A buyback of the bonds would allow Kohlberg Kravis to sidestep provisions requiring the firm to guarantee the price of the bonds by next April.

The plan is likely to lower the return for Kohlberg Kravis and its investors. But without a recapitalization, RJR Nabisco would end up paying a higher interest rate on the bonds.