UPDATE 6-Blackstone wins EOP battle for $23 billion

(Adds comments from Equity Office CEO, investor; details on selling NY buildings; and closing stock prices)

By Mark McSherry

NEW YORK, Feb 7 (Reuters) - Private equity firm Blackstone Group won a 3-month bidding war to acquire Equity Office Properties Trust EOP.N on Wednesday after a majority of the top U.S. office landlord's shareholders accepted Blackstone's $23 billion bid and Vornado Realty Trust VNO.N dropped out.

Blackstone will pay $55.50 per share in cash for Equity Office -- the largest office landlord after the U.S. government.

Vornado withdrew its $56 per share cash and stock proposal earlier on Wednesday, saying the premium it would have to pay would not be in shareholders' interest.

"We're pretty confident we got full value out of the transaction," Equity Office Chief Executive Richard Kincaid said.

Nonetheless, he said the transaction "is a little bittersweet for all of us."

Blackstone, has been one of the private buyers driving up real estate investment trust (REIT) stocks. These buyers have been able to finance their purchases with 80 percent to 95 percent of debt. But public companies, subject to shareholders' approvals and rating agencies, are constrained in their use of leverage.

Publicly traded office REITs provided investors with a 39.8 percent return in 2006, beating the overall return of 29.5 percent for all equity REITs in the FTSE NAREIT U.S. Real Estate index. The Standard & Poor's 500 .SPX returned 15.8 percent in the same period.