ROCKY MOUNT, N.C. (AP) _ Roy Rogers restaurants has again killed the most popular television ad it's ever run, after the spot drew criticism last week from the same group that protested it the first time around.

The advertisement features women serving plates of food in a school cafeteria. The spot, with ''See You in September'' in the background, encouraged school children to come eat at Roy Rogers before they're faced with nine months of cafeteria food.

The ad first appeared in the summer of 1988 and became ''one of the highest awareness-level commercials'' in the fast food industry, said John Merritt, vice president for public relations at Hardee's Food Systems.

But Marriott Business and Food Services Management, which owned Roy Rogers at the time, also provides food to school systems, airlines, universities and other customers.

''The Institutional Food Workers of America came unglued and jumped on Marriott with both feet,'' Merritt said.

The cafeteria ad was revived last week by Roy Rogers' marketing department in Rockville, Md. But the spot has been axed yet again.

''The same people predictably came unglued,'' Merritt said.

He said Hardee's is not in the cafeteria business, but decided that the ''See You in September'' ad reflected poorly on the entire food service business.

''(It's) just not becoming to us to be poking fun at them,'' he said. ''You need to put the shoe on the other foot.''

Hardees, which bought Roy Rogers from Marriott in January for $365 million, plans to transform the 648 Roy Rogers restaurants into Hardee's on a market- by-market basis, with all of them converted by summer of 1991.