The Kaufman Organization, in a new joint venture with Principal Real Estate Investors, has signed a 99-year net lease with Extell Development Company to redevelop four vacant Manhattan commercial buildings in Midtown South.

The 11- and 12-story buildings total more than 341,000 square feet and are at 13-15 W. 27th St.; 45 W. 27th St.; 19 W. 24th St.; and 119-125 W. 24th St., between Fifth and Seventh avenues.