In an effort to bolster its flagging ratings, CBS announced Monday that it has picked up the longrunning NBC program NBC Nightly News. CBSwhich paid $150 million for the rights to the highly rated news program after a lengthy bidding war with NBC, ABC and Foxwill run NBC Nightly News in its 7:30 p.m. EST time slot, immediately following CBS Evening News. 'We are delighted to welcome the newest member of the CBS family,' CBS president Laurence Hewitt said. 'Tom Brokaw and Dan Rather are nighttime televisions new dream team. When put back to back, these two powerhouse shows form the most unbeatable, exciting hour of news anywhere.' NBC will also air reruns of CBS Evening News weeknights at 11 p.m. EST, followed by Fox Tuesday Night At The Movies. 