Keith Olbermann -- Planning His Exit Long Before He Was Fired

Keith Olbermann wanted out of Current TV well before he was fired yesterday because he felt the network was mismanaged and wouldn't be around much longer ... sources close to the situation tell TMZ.

As TMZ first reported, Keith is planning on filing a lawsuit against the network for his unceremonious dumping yesterday. He released a statement that said in part, "It goes almost without saying that the claims against me implied in Current's statement are untrue and will be proved so in the legal actions I will be filing against them presently."

According to our sources, Keith felt the network was a "ragtag operation" that was disorganized and felt thrown together. We're told Keith felt the entire place was mismanaged ... right down to the office supplies.

On one such occasion, we're told the staff couldn't use one of the printers because it was out of toner and they had none in supply. In a staff-wide email obtained by TMZ (see below), a production administrator told the staff, "We expect to have replacement toner in tomorrow and will have a better stock on hand for the future. Sorry for the inconvenience."