Underwriting sales agency bought by NPR, WGBH

The largest producing organizations in public radio and TV, NPR and WGBH, said in a release today that they're buying what is probably the largest broker of underwriting time on local stations, Boston-based National Public Broadcasting. It represents 60 stations in pubTV, 120 in pubradio, NPR, NPR.org, PBS.org and the NewsHour. Bob Williams, a sales exec who had built an earlier business selling ad time on cable TV, established the business 10 years ago as National Public Television and later expanded into radio.