A major Yahoo! shareholder blasted the company over its strategic review, which he thinks will take the company in reverse not forward.

Daniel Loeb, CEO of hedge fund Third Point, wrote a letter to Yahoo!’s board yesterday accusing founder Jerry Yang of double-dealing as the company negotiates with potential partners and buyers.

Loeb called for the removal from the board of Chairman Roy Bostock and Yang and for Third Point to choose two new members.

“We are deeply concerned by news reports that you are considering a leveraged recapitalization that will allow private equity firms to gain substantial equity positions that will, when combined with Jerry Yang’s and David Filo’s ownership, effectively establish a controlling position in Yahoo,” Loeb wrote.

“More troubling are reports that Mr. Yang is engaging in one-off discussions with private equity firms, presumably because it is in his best personal interests to do so,” Loeb wrote.

The investor was referring to Yang’s role in trying to unite with private-equity firms to pour money into Yahoo! and gain a controlling share in the company.

Yahoo! is trying to force interested firms into signing a nondisclosure agreement if they want access to key company financial data. So far, KKR and TPG have signed the agreement, a source with knowledge of the negotiations said. Several others have balked, including Blackstone, Silver Lake and Providence Equity Partners.

“Yahoo! is trying to get private equity to sign the agreement and by doing so it takes them off the playing field,” the source said. “If they’re trying to maximize shareholder value they would not be going through that kind of process. ”