Williams -10% premarket as most actively traded stock

• Williams Cos. (NYSE:WMB) -10.4% as volume tops 6.1M shares ahead of the open, making the stock the most actively traded in the premarket.
• WMB announced after yesterday's close that it would increase its dividend for the March quarter by 50% to $0.30/share and issue 65M common shares to finance the purchase of 289M units of Williams Partners (NYSE:WPZ) at $36.09/unit; WMB priced the 65M-share offering at $29.
• WMB says it will use the proceeds from the sale to help boost its stake in WPZ to 72%; WPZ -1.2% premarket.