NBC has picked up another season of the Donald Trump franchise “Celebrity Apprentice.”Show is set to air in spring 2010. Pickup comes as the show has performed solidly for NBC as a two-hour weekly skein. Season to date, “The Celebrity Apprentice” is averaging a 3.5 rating/ 9 share among adults 18-49 and 8.6 million viewers. Show has improved the Sunday 9-11 p.m. slot’s non-sports average by 39% with adults 18-49. “It’s a valuable franchise and proven competitor,” said NBC U alternative chief Paul Telegdy. “The Apprentice,” which first bowed in January 2004, is now in its eighth cycle — the last two having been reworked as “Celebrity Apprentice.” Trump and Mark Burnett are behind the show. Burnett, Trump, Page Feldman and Eden Gaha exec produce.