Both the rumor mill and heavy stock trading point to the possibility that Arden Realty ( ARI), one of Southern California's largest office owners, may become the next real estate investment trust to go private. The rumor was first published by Barry Vinocur, a veteran REIT industry watcher, in his REIT Newshound note late Thursday. Vinocur cited an unnamed source who said an announcement is reportedly imminent on a deal that would take Los Angeles-based Arden private. The deal would involve a breakup privatizing Arden, with one or two public REITs also taking pieces of the company, he wrote. After barely moving for the past month, Arden shares rose 4.5% Thursday to $40.40, with heavy trading volume. It isn't the first time that Arden has been the subject of buyout speculation. "Management has always indicated there is a price at which to sell," one major institutional investor in the company told TheStreet.com. Arden didn't return a call seeking comment. Industry watchers expect more REITs might go private since share prices in the sector have taken a beating recently on interest rate fears. This year, Capital Automotive ( CARS), Gables Residential ( GBP), and CRT Properties ( CRO) all approved plans to go private and investors were rewarded with premiums that ranged from 9% to 15%.