NEW YORK CITY--SL Green Realty Corp. refinanced its 47-story class A office tower at 919 Third Avenue, which it owns in a joint venture partnership with New York State Teachers Retirement System. The 12-year $500 million mortgage was jointly originated by Metropolitan Life Insurance Co. and Pacific Life Insurance Co.

At fixed rate of 5.116%, the loan matures in 2023 replaces the former 10-year, $250-million loan on the 1.4-million-square-foot property, which carried a balance of $218 million at payoff with a 6.867% interest rate and was set to mature in August 2011, SL Green says in a statement announcing the deal.

Running the full block-front between 55th and 56th streets, tenants here include law firms Debevoise & Plimpton and Schulte Roth & Zabel, global banking giant BNP Paribas and direct marketing specialist Draft Worldwide. HFF arranged the refinancing on behalf of the joint venture. Asking rents in the building range in the mid-$60s per square foot, according to SL Green’s website.