City's board have held talks with numerous outside parties willing to buy the Premier League club outright, but none prepared to accept the terms currently available.
"Thaksin is happy to sell off a chunk but wants to retain the majority," said City chief executive Garry Cook.
"But they - potential investors - want all of it. Everybody wants all of it. They all want a football club.
"I have had representatives of companies from Dubai, Saudi Arabia and Kuwait on to me.
"Some of them have phoned the supporters club because they couldn't find the club number. So I get the supporters club asking me if the club is for sale. So I've got to deal with all that.
"We tell them that the club isn't for sale. We are looking for new investment. It might not be the selling of a stake, and we've got five or six options.
"The reason we want to do that is because we're in the transfer window and we need three or four players."