Sprint Corp., Sprint Spectrum and RadioShack announced an alliance wherein Sprint-branded communications services--including PCS, paging, long distance, wireless, Internet access and prepaid calling cards--will be sold at RadioShack. A joint marketing and co-branding campaign is planned for the third quarter of 1997. J. Walter Thompson USA, San Francisco, is agency for Sprint, while Sprint Spectrum earlier this year tapped Hal Riney & Partners, San Francisco, as its agency. A partnership of Sprint, Tele-Communications Inc., Cox Communications and Comcast Corp., Sprint Spectrum plans to offer personal communications services (next generation wireless service) in about 300 RadioShack stores in 15 cities by yearend.