NEW YORK—The New York office of Hines, the international real estate firm, announced today that Simpson Thacher & Bartlett LLP has executed an agreement to renew its lease for 595,000 sq. ft. at 425 Lexington in Midtown Manhattan. Encompassing 26 floors of the 31-story building, the lease will be reset to expire in 2033. The lease extension will become effective subject to typical lender consent or upon completion of the sale and payment of the mortgage, which is due in August 2013.

Lewis Miller, Ken Rapp and Ramneek Rikhy of CBRE represented Simpson Thacher in lease negotiations, while Hines represented the owner, its Hines U.S. Core Office Fund.

“We have enjoyed a long relationship with Simpson Thacher, and their confidence in and recommitment to 425 Lexington Avenue speak volumes about the quality of this unique asset,” Tomm Craig, Hines senior managing director for its New York office, said in a statement.

“We have been pleased to be a tenant at 425 Lexington under Hines’ ownership, and we are happy to have secured 425 Lexington to serve as our world headquarters for at least another two decades,” Simpson Thacher COO Michael Hersch said in a statement.

In early March, Hines announced that the building would be marketed for sale by Eastdil Secured and CBRE.

“Simpson Thacher’s renewed commitment to 425 Lexington dramatically highlights the attractiveness of the asset while solidifying and stabilizing the long-term returns to an investor,” Eastdil Secured Senior Managing Director Douglas Harmon said in a statement.

The 750,000-sq.-ft. building occupies the entire easterly block front between 43rd and 44th streets and is situated directly across from Grand Central Terminal and the Chrysler Building.