NBC confirmed Tuesday that it had hired Ben Silverman, a former agent with the William Morris Agency and the founder of the independent production company Reveille, to take over creative and programming authority at the network. He'll replace NBC Entertainment President Kevin Reilly and be given the title of co-chairman of NBC Entertainment and NBC Universal Television Studio. The other co-chairman will be Marc Graboff, who had previously held the position of president of NBC Universal Television, West Coast and will oversee the company's business and administrative operations. The network said that, contrary to earlier speculation, it does not plan to buy Reveille but that it had agreed to extend a first-look deal with the company for two more years. Silverman said that he will retain an interest in Reveille but insisted that it would not benefit from his NBC position. In announcing the executive shake-up NBC Universal CEO Jeff Zucker did not indicate whether Silverman will receive the wherewithal to develop new shows and standbys for those that fail. The network has been hit hard by cost-cutting in recent years, even as its ratings plummeted.