AT&T Co and NCR Corp have been dividing up their large accounts, putting the most logical choice in charge so that NCR is responsible for J C Penney Co, the big retailer, while AT&T drew AMR Corp’s American Airlines. Meanwhile there are strong indications that very few of AT&T’s middle and upper managers will be making the transition to NCR: the way they’re playing, however, it’ll be the end of the summer before we know for sure. AT&T Computer Systems president Rich McGinn is skeptical of this hunch, but admits in the same breath that he doesn’t know for sure how it will all shake out. He does, however, say that AT&T sales are ahead of last year, and ahead of this year’s projections.