NCR Tells Suitor AT&T; a Friendly Merger Is Possible : Takeover:The deal hinges on how much protection the phone giant will offer to the computer firm’s shareholders.

NCR Corp. inched closer on Tuesday to agreeing to American Telephone & Telegraph Co.’s $7.48-billion takeover offer, with NCR’s chairman saying he will accept the $110-a-share bid if A&T; strengthens its price guarantee.

“The hard part should be over,” NCR Chairman Charles E. Exley Jr. wrote in a letter to AT&T; Chairman Robert E. Allen. “Now is the time to get on with the friendly merger you have wanted for five months.”

In his letter, Exley said he would recommend the offer to NCR’s directors if the phone firm ensures that NCR shareholders receive $110 a share in AT&T; stock, even if the stock drops as low as $32.50 per share. AT&T;’s latest offer provides a price guarantee, but only if AT&T; stock stays at $35.50 per share or above.

AT&T; had no response to Exley’s latest demand late Tuesday.

However, analysts said they expect that a deal will soon be reached and AT&T; will finally win its protracted takeover battle for the nation’s fifth-largest computer maker.

The latest chapter of the saga began Friday when AT&T; boosted its bid to the equivalent of $110 a share, by offering 2.943 shares of its stock for each share of NCR stock. However, the offer, worth a total of about $7.48 billion, was based on AT&T;’s stock being worth $37.375 per share, its closing price Friday.

But Exley refused to support the new offer without assurances that NCR shareholders would be protected if AT&T; stock drops. In its latest proposal, AT&T; offers a maximum of 3.099 of its shares for each share of NCR stock, a ceiling that guarantees the $110-per-share price should AT&T; stock fall as low as $35.50 per share. On Tuesday, AT&T; stock closed at $36 per share, down 12.5 cents.

Exley’s counterproposal calls for NCR shareholders to receive a maximum of about 3.385 shares of AT&T; stock for each NCR share, which guarantees the offer price if AT&T; stock slides to $32.50 per share.

Exley noted that the $32.50 floor is the average closing price of AT&T; stock between Dec. 3, 1990, when the takeover was launched, and last Friday.

“Now is the time for us both to be reasonable and flexible,” Exley wrote to Allen. “Our shareholders need appropriate protection against the risk of a fall in the price of AT&T; stock. . . . It is only reasonable to expect that you would protect NCR shareholders at least down to the average closing price of your stock over the duration of your offer.”

AT&T; has been trying for the past 4 1/2 months to buy NCR to bolster its own sagging efforts to enter the computer business and blend its telecommunications network with the growing field of computerized data communications.