Comic Jeff Foxworthy has signed a deal to star in a half-hour sitcom through Viacom Prods., the company confirmed, under the first joint talent deal between the production unit and sister Viacom company Showtime Entertainment Group.In addition to the pilot, the agreement calls for Foxworthy to appear in two more comedy specials to air on Showtime, having headlined a pair of earlier spex on the pay service. The agreement underscores efforts to create more cooperation between divisions at Viacom, particularly in developing network programs. Viacom Prods. has also announced plans for a CBS pilot based on the cable series “Clarissa Explains It All,” which airs on Nickelodeon, another Viacom-owned cable network. The pilots also represent an effort to push into half-hour comedies under Perry Simon, who recently joined the company as president of Viacom TV, West Coast. “We’re trying to get into that (comedy) and going about it in a non-traditional fashion,” he said. Foxworthy — who starred last year in the MTM/CBS in-house pilot “Banner Times,” which featured him as a newspaper publisher in the small town of Banner, Ga. — remains one of the comedy circuit’s most popular stand-ups. His country-flavored act has led to a Warner Bros. album and five books, highlighted by his “You Might Be a Redneck If …” The comic is repped by United Talent Agency. Viacom’s current network roster includes older-skewing one-hour series like “Matlock” and “Diagnosis Murder” as well as the “Perry Mason” movies, all produced in association with the Fred Silverman Co. and Dean Hargrove Prods. Last season it did sell one half-hour comedy, “Flying Blind,” ultimately canceled after a season onFox Broadcasting Co.