The expected buyer of Bert Lance's bank stock is a publicity-shy Atlanta businessman who doubts the budget director would remember him although they have met twice - once at Tiffany's and again at Jimmy Carter's inaugural.

Described by associates as a "very introspective, intellectual man," David N. Smith, 39, has reportedly wanted a "bank of his own" for several years now, ever he had his credit lines canceled on an earlier business that was forced into liquidation.

Smith was named yesterday by the Atlanta Journal and the Atlanta Constitution as the hitherto anonymous purchaser who had been lined up to buy the 200,000 shares of National Bank of Georgia stock that Lance had promised to sell.

A native of Canton, Ohio, who moved to Atlanta some 10 years ago, Smith now heads a company called International Horizons Inc., a $25 million a year business that sells instructional books and casettes, primarily in Japan and more recently in Brazil, on how to learn English.

The firm has also branched out into sales of biorhythm calculators, handheld gadgets designed to program various emotional, physical and mental aspects of your personality and tell you on any given day when you are in your cycle and what your potential is.

If Smith uses one himself, it evidently advised him to remain aloof from the press. His Japanese-born wife told one reporter that he was at the office. His office told another reporter that he was out of town.

"He's a very aggressive businessman and a hard-working salesman who's had a tremendous success," said Atlanta construction executive Daniel B. Pattillo, a director of the National Bank of Georgia and currently its largest single shareholder.

According to Atlanta Journal reporter Paul Troop, who succeeded in putting several questions to Smith through an intermediary, Smith was interested not so much in helping out Bert Lance but rather in acquiring control of the National Bank of Georgia.

The reason, it was said, is that several years ago, Smith had developed a successful business selling encyclopedias abroad when an unidentified Atlanta bank pulled his credit lines and demanded immediate repayment, forcing Smith to liquidate the operation.

"He came to the conclusion then," a close associate was quoted as saying, "that the only way he could really feel comfortable about dealing with banks was to own one."

The quest could prove good news for Lance who stands to reap a good enough advice to pay off his outstanding $3.4 million loan from the First National Bank of Chicago and then some, and for the National Bank of Georgia, which stands a gain a $6 million infusion of capital.

If the purchase plan taking shape in Atlanta goes through, according to several sources, Smith will buy an option for Lance's 16 per cent stock ownership in the Atlanta bank - for a price equivalent to the interest Lance owes on his Chicago bank loan. Then in the fall, when Lance's stock is free from banking regulations inhibiting the sale of some of it. Smith will exercise the option, and will pay off the Chicago bank loan and perhaps a bit more.

One source reported that the price to be paid is leveling off at $17.50 a share, $2 above book value and some $5 above the market price.

But Smith reportedly wants more stock than that. After he buys Lance's 16 per cent, sources say, the National Bank of Georgia is expected to offer existing shareholders a $6 million issue of convertible debentures, with Smith waiting to buy $5 million. He could then convert those certificates into stock, giving him 35 per cent of the bank.

That part of the deal would give a boost to the NBG, which has had to write off some $2.8 million in real estate loans turned sour since Lance left and is expected to be forced to cancel its customary 20 cent dividend for the second quarter.

Pattillo, whose 212,000 shares gives him a 17 per cent interest in the bank, said, however, that he hasn't agreed to the second part of the plan yet. "There's still a good deal of negotiations [to be done] in this area," he said. He said he would "not agree to any debenture offer unless each stockholder had an opportunity to buy his pro rate share" - a formula that would enable Pattillo to remain the leading stockholder.

Asked if Smith wants the bank to help out his business, Pattillo said he didn't think so and suggested that Smith simply looks on it as "a doggone good, long term investment."

Lance's trustee, Dalton, Ga., businessman Tom Mitchell, could not be reached for comment, but he has said he expects the purchase of Lance's stock to be completed in a day or two.

Described by friends as a lifelong Republican, Smith said through his intermediary that he still donated $1,000 to the Carter presidential campaign because "he's a Georgian and I was impressed with him," the Atlanta executive was also said to be a friend and financial supporter of Atlanta Mayor Maynard Jackson.

As for Lance, Smith told associates that their two encounters, at Tiffany's jewelry store in Atlanta and at the inaugural, were so brief that he didn't think the budget director would recall them.