The 81-year-old, who took over the club in 2005, will attend his final game at Elland Road as chairman on Saturday when Leeds face Brighton & Hove Albion.
Bates has said that the club had to wait until GFH Capital completed their takeover of the club before they could change manager.
He told the Yorkshire Evening Post: "What people won't be aware of is that two clauses were included in our agreement with GFH. One was that we could make no material change without consulting GFH, while the other was that Neil Warnock had to stay as manager.
"It meant any player bought or sold from June  onwards had to be discussed and approved by [Leeds director] Salem Patel, on behalf of GFH. We were happy to do that because, as I say, we thought the takeover would go through during the summer.
"Unfortunately, it didn't and, instead, the deal wasn't done until December 21. A consequence was that we had to keep Neil Warnock. I wanted to sack him in October because I didn't think it was working out. But I couldn't because of what was happening with the sale."
Leeds parted company with Warnock in April.