NEWARK, N.J. (AP) _ Supermarkets General Corp. said Wednesday it agreed to be acquired in a leveraged buyout valued at about $1.8 billion.

The investor group making the offer is led by a unit of Merrill Lynch & Co. and some senior executives of Supermarkets General, but does not include Supermarkets General's chairman and chief executive, Leonard Lieberman.

The proposal represents the second major buyout attempt orchestrated by Merrill Lynch in as many weeks. The investment firm also is leading a group that on April 10 announced an agreement to acquire Borg-Warner Corp. for $4.2 billion.

The definitive agreement involving Supermarkets General calls for the investor group to make a cash tender offer of $46.75 a share for up to 32.8 million, or 85 percent, of the company's 39.7 million total common shares and equivalents outstanding.

The group offered to exchange each of the remaining shares for a package of debentures and preferred stock in the surviving company.

The agreement, which was approved by Supermarkets General's directors, came two weeks after Dart Group Corp. withdrew an unsolicited offer to buy Supermarkets General for more than $1.7 billion.

Dart, a Landover, Md.-based discount retailer, initially offered in March to pay $41.75 a share, then later sweetened the bid to $42 a share in cash and preferred and common stock in the surviving company.

After Dart pulled out, Supermarkets General's common stock drifted in open- market trading to about $41 a share from $45. But following the Merrill Lynch announcement, the stock jumped $4.75 a share to close at $45.87 1/2 on the New York Stock Exchange.

Dart, which still owns about 1.9 million, or less than 5 percent, of Supermarkets General's stock, had said it remained interested in buying the company despite withdrawing its recent offer.

Dart President Robert M. Haft was not immediately available to comment on the Merrill Lynch offer, his office said.

The Merrill Lynch group said the leveraged buyout was subject to at least 51 percent of Supermarkets General's stock being tendered, and to the group reaching definitive agreements for obtaining the necessary financing.

The group noted, however, that it already had received financing commitments from Merrill Lynch & Co., Bankers Trust Co. and other lenders.

In a leveraged buyout, the purchase is made by a small group of investors with mostly borrowed money that is repaid with the target company's cash flow or asset sales.

Supermarkets General, based in Carteret, N.J., is the nation's eighth- largest food retailer. It operates 137 Pathmark grocery stores in the Northeast, along with Purity Supreme and Angelo's supermarkets, and the Rickel chain of hardware stores.

Lieberman said in a statement that while negotiating the purchase agreement ''it became clear that the interests of everyone connected with this transaction would be best served by my not participating in the new company.''

He did not elaborate on his reasons for leaving, but emphasized that the newly acquired company would be ''guided by the best possible team into a prosperous future.''

A Supermarkets General spokesman, Robert Wunderle, said Lieberman's exit was ''really a function of his age.''

''He's 58 and significantly older than the folks involved'' who will be making long-range plans for the company, Wunderle said.

Succeeding Lieberman would be Pathmark President Kenneth Peskin, and James D. Dougherty, executive vice president of the parent company, would become president. Jack Futterman, president of Supermarkets General's drug store merchandising division, would become vice chairman.

Peskin, Dougherty and Futterman are the principal management members of the buyout group, Wunderle said.