While declining to elaborate, Disney and Walden Media confirmed Tuesday that for budgetary and logistical reasons the Burbank-based studio is not exercising its option to co-produce and co-finance the next "Narnia" movie with Walden.

The third entry in the series, based on the classic books by C.S. Lewis, was in pre -production and set for a spring shoot for a planned May 2010 release. The development puts the participation of the talent attached in doubt. Michael Apted was on board to direct a script by Steven Knight. The key players of the second installment, "Prince Caspian" -- Ben Barnes, Georgie Henley, William Moseley and Anna Popplewell -- were to return for the third film.

Walden has a strong relationship with the Lewis estate and will shop "Treader" in hopes of finding a new partner. The most likely candidate at this stage is Fox, which markets and distributes Walden fare under the Fox Walden banner.