NEW YORK, DEC. 2 -- Shearson Lehman Bros. Holdings Inc. was reported today to be close to an agreement to acquire E.F. Hutton Group Inc. in a $1 billion deal that would create one of the nation's biggest investment firms.

There was no official comment from either company by late today. But a source close to the negotiations said the details had been agreed on by top managers and the proposal had been presented to Hutton's board for consideration.

Another source said the matter was delayed by technical matters and predicted the agreement would be approved.

Sources inside Hutton said that although employes had not been notified officially, the rank and file viewed a merger with Shearson as a foregone conclusion. Shearson reportedly told employes over its interoffice speaker system that an agreement was coming.

The 84-year-old Hutton began seeking a buyer or major cash infusion last month amid concerns over its ability to continue raising capital following the stock market collapse in October.

For Shearson, the acquisition of Hutton would be a coup that would vault it past Salomon Inc. as the nation's biggest investment firm, dramatically expand the size of its retail sales force and create new uses for its recently expanded computer processing facilities.

Hutton had about $1 billion in capital at the end of 1986, making it the nation's 10th largest investment firm. Shearson was No. 2 with about $3.1 billion in capital, behind Salomon Brothers Inc.'s $3.2 billion.

The deal also could help Hutton shake the taint of recent scandals and erratic financial performances, but also might mean the sale of some major operations or widespread layoffs of Hutton workers that Shearson does not need, analysts said.

According to a report by Dow Jones News Service, Shearson offered to pay $25 per share in cash and $8 in preferred Shearson stock, which carries a market value of about $5 per share. Hutton has 34.2 million common shares outstanding, giving the proposal a value of about $1.03 billion.

Several other companies had considering making a bid for Hutton since the firm put itself up for sale Nov. 23, little more than a year after informal merger talks with Shearson had broken down.

Dean Witter Financial Services Group Inc., Merrill Lynch & Co. and Equitable Life Assurance Society of the United States all had expressed interest in buying Hutton.

A key target for Shearson was Hutton's worldwide retail network, which would add about 6,500 seasoned account executives to Shearson's own 5,700 brokers, rivaling Merrill Lynch for dominance in that area.

Shearson, which has about $75 billion in funds under asset management, also would gain billions of dollars in that relatively stable business.

But at the same time, duplication among back office functions and other areas make it likely that Shearson will cut as many as 5,000 of Hutton's 18,000 employes, while attempting to retain top performers, analysts have speculated.

There have been market rumors that Shearson might attempt to sell Hutton's capital markets operations, considered some of the firm's weaker areas, which would reduce the scope of any layoffs.

The biggest cloud over Hutton was its 1985 guilty plea to 2,000 counts of federal mail and wire fraud stemming from a check-overdraft operation. To many people on Wall Street, the scandal was an indictment of Hutton management that pointed out sloppy practices that were tarnishing the company's earnings as well as its reputation.

In 1986, a boom year for the stock market and investment business, Hutton lost $90.3 million. The loss stemmed from a special $130 million fund that was established largely to compensate customers for losses from certain municipal bonds the firm had marketed and traded improperly.

In addition to the existing worries, Hutton officials said the stock market's October collapse raised new concerns about the firm's ability to raise capital needed to remain competitive in the volatile global financial markets