The BBC and the Discovery Channel appeared set to unveil an ambitious trans-Atlantic alliance Thursday that will launch a new TV channel, BBC America, in the United States. The BBC said Wednesday it will hold a news conference to announce details of a partnership with Discovery Communications Inc. The companies are widely expected to announce the launch date and programming plans for BBC America, as well as a co-production funding deal and the launch of two global channels - "People and Arts" and "Animal Planet." (c) Reuters