5:38pm: HoopsHype reports that Ibaka's deal is actually guaranteed for $49MM and could pay him as much as $51.5MM based on unspecified individual and team incentives.
11:59am: The Thunder have officially announced Ibaka's extension.
6:38am: Ibaka's deal is worth $48MM over four years, a league source tells Adrian Wojnarowski of Yahoo Sports (via Twitter).
2:24am: Yahoo's Adrian Wojnarowski reports that Serge Ibaka has agreed to a four-year deal worth at least $40MM to remain with the Thunder. The three-year veteran averaged 9.1 PPG, 7.5 RPG, and a remarkable 3.7 BPG in 27.2 MPG as Oklahoma City's starting power forward last season. Although Ibaka's rebounding and block averages dipped a bit during this year's playoffs (5.8 RPG/3.0 BPG), it would be somewhat challenging to question the Thunder's decision to ensure an extension for a 22-year-old core player with premier defensive abilities and NBA Finals experience rather than let him test the free agent market after the 2012-13 season.
Wojnarowski adds that with Kevin Durant and Russell Westbrook playing on maximum contracts (along with $27MM due to Kendrick Perkins over the next three years), Oklahoma City faces a difficult decision with James Harden, who could possibly garner a maximum contract offer next summer as a restricted free agent.
Hoops Rumors' Chuck Myron examined Ibaka's value as an extension candidate earlier this month.