UPDATE 2-SL Green refinances Times Square tower

* SL Green refinances mortgage

* Uses less equity than expected

* Stock down 1.86 percent (Adds equity contribution, byline, updates stock price)

By Ilaina Jonas

NEW YORK, Jan 5 (Reuters) - New York office landlord SL Green Realty Corp (SLG.N) on said it refinanced the mortgage on the Times Square office building that is home to media company Viacom Inc VIAb.N with a lower mortgage, eliminating some of its debt.

The real estate investment trust said Tuesday it closed on a $475 million refinancing of 1515 Broadway with a five-year floating rate mortgage. The new loan replaces the former $625 million mortgage that was set to mature in November.

SL Green owns 1515 Broadway in a joint venture with SITQ, the real estate investment arm of Canadian pension fund Caisse de Depot et placement du Quebec. The joint venture will contribute $150 million in equity. However, SL Green declined to disclose its equity contribution.

The loan was provided by a syndicate led by the Bank of China that included DekaBank and Landesbank Baden-Wurttemberg.

Viacom signed a 1.27 million square foot lease renewal in November 2008 that goes through mid-2015. The tower is also home to the Minskoff Theatre and AEG Live's Nokia Theatre.

Last month, Chief Executive Marc Holliday said at the company's annual investor meeting that it expected to announce the refinancing within a month. Holliday also said the loan required SL Green to pay down significantly less equity than it projected in May.

Shares of SL Green closed down 1.86 percent at $48.02 on the New York Stock Exchange. The shares gained 94 percent last year, compared with a 21 percent rise for the benchmark MSCI U.S. REIT Index .RMZ (Editing by Tim Dobbyn and Steve Orlofsky)