Network news veteran Jeff Gralnick is stepping aside as executive vice president of business news for CNN and producer of the Moneyline News Hour,' a year after arriving from ABC. Replacing him is another ABC News veteran, Katherine O'Hearn. O'Hearn, who has been with ABC News for 17 years, most recently produced the network's weekend editions of World News Tonight. She was recently passed over for the executive-producer slot of the weeknight version of World News Tonight in favor of Paul Slavin. Gralnick, 61, said he is considering a number of other opportunities.