The long-in-the-making merger between national sports services SportsChannel America and the Prime Network has come to a close with an announcement of the deal expected as early as today, according to sources familiar with the agreement.Discussions between Liberty Media, managing partner of Prime, and NBC/Cablevision, owners of SportsChannel America, have been on and off for more than a year, although they are said to have concluded with the final signatures on the deal coming during the recent holiday period. Daniels & Associates is also a part owner of Prime, although Liberty fronted the talks this time around. Moreover, current SCA president Jeff Ruhe is expected to stay on with the new venture heading the operation out of New York, while Daren Miller, currently director of business development with TCI/Liberty Sports, is moving from Denver to Houston to head up the Prime side of the venture. SportsChannel America launched in 1988 as a backdrop service for its regional sports networks. Ideally, the local services use SCA to fill in any gaps within their programming schedules. The service launched with the National Hockey League as its main sports attraction and at the time projected its then 8 million home subscriber base to grow to 25 million to 30 million by the end of the package. However, the growth never came. SCA lost its bid for an option year with the NHL, which would have included the current season. The Prime Network launched as another backdrop service for its regionally owned and affiliated cable sports services and rapidly grew. Merger discussions heated up several times during 1992, with the deal being on then off many times. According to some familiar with this arraignment, the necessary signatures have been acquired and the deal is pending regulatory approval. The new service is expected to reach about 35 million subscribers.