ABC has signed country star Billy Ray Cyrus to an agreement to star in two prime time specials and a TV movie, with the first one-hour special to air early next year.Cyrus’ debut album “Some Gave All” and the single “Achy Breaky Heart” both topped the country music and pop charts, and the latter was named single of the year at the Country Music Assn. Awards. The specials mark the first such project by the Mercury Records artist, who made his first national TV appearance on cable web TNN’s “Nashville Now” program. The networks have taken a greater interest in country music over the last year or so, drawn by high ratings for country awards shows and the crossover appeal of several current stars. NBC, for example, did OK last season with the weekly variety series “Hot Country Nights,” lassoed big ratings with its special “This is Garth Brooks” and has a series in development for Kenny Rogers. ABC’s current series “Delta” also features a country music element.