LOS ANGELES, Oct 3: When Britney Spears takes the stage this December for the first of a heavily hyped 100-show two-year residency at Planet Hollywood in Las Vegas, the loudest cheers may come from her insurance underwriters. Along with the sound engineers and roadies who help stage a concert, insurance underwriters play a large role in making sure a star can get onstage and grab the microphone. Insurers are also key during those times when stars do not show and concerts get canceled. (agencies)