ATLANTA (AP) _ Developer Donald J. Trump, whose lawyers often are busy fighting unauthorized attempts to use his name, has agreed to endorse a line of photographic business cards made by a small Georgia company he had sued for calling the product ''Trump Cards.''

Under an out-of-court settlement announced Wednesday, Trump was given the rights to the ''Trump Cards'' trademark and will license Positive Concepts Ltd. of Lithia Springs, Ga., to market the product. Trump will receive a monthly royalty.

Trump agreed to drop his suit against PCL, a suburban Atlanta company that began making the cards in 1983. The company, whose trademark application last year prompted Trump's lawsuit, contends it named its product for the high- ranking suit in a card game rather than the billionaire entrepreneur.

PCL President Edward A. Zito said Wednesday the settlement was beneficial to both sides. He said his company avoided a potentially lengthy and expensive court battle and got an unusual endorsement from Trump that should boost the fortunes of his business.

Advertisements featuring Trump's endorsement will begin appearing in national business magazines this spring, Zito said.

''We are quite honored that someone of Donald Trump's position would give us his personal endorsement,'' Zito said. ''We couldn't get anybody better to endorse our product, and we're not paying for it.''

Neither Zito nor Joe Silver, a spokesman for The Trump Organization in New York, would say how much money Trump would receive in royalties.

Zito said, however, the figure was nominal to someone like Trump.

''Let's face facts - he's a billionaire and we're just coming along as a company,'' Zito said. ''What's it to him if he got five, ten, $15,000 a year?'' Zito said the path to the settlement began last summer when he called Trump to discuss the suit over the cards.

''He was cordial but stood his ground,'' Zito said. ''I said, 'You know, we didn't try to steal your name from you. In 1983, nobody knew of you.'''

Zito said he followed up the call by sending Trump a sample of the cards and suggested the issue could be settled out of court. Trump liked the cards, Zito said, and months of negotiations began.

''I like your Trump Card photographic business cards and think they have great potential. The outdated, printed business card is long overdue for a change,'' Trump said in a letter late last month to Zito.

Trump, whose lawyers usually pounce on any attempt to use the Trump name, pursued a settlement in this case because he liked the product, Silver said.

''We're constantly involved in lawsuits against people trying to trade on Mr. Trump's name, and writing cease and desist letters,'' Silver said.

Silver said most cases end up with a permanent injunction against use of the name by unauthorized parties. ''We haven't lost a case,'' he said.

But Zito maintained that he never had Donald Trump in mind when he named his product ''Trump Cards.'' And he said he never intended to try to land a gold mine by fighting Trump over the name.

''I think that's one of the things he liked ... that we didn't want any money out of him,'' Zito said.