Out of the top 50 commercial office leases that were signed in Manhattan back in 2007, the 6th largest was secured by advertising and marketing firm Grey Global Group for a new 370,000-square-foot headquarters at L&L Holding Company's 200 Fifth Avenue. (You may recall that for both calendar years 2007 and 2008, we identified commercial leases that were secured in green buildings, LEED-certified or otherwise, from CoStar's list of the 50 largest deals of the year here in New York City). Last week, Grey actually moved into its new space at 200 Fifth Avenue, where L&L continues to seek formal LEED for Core and Shell certification from USGBC in connection with its $100 million renovation effort of the 100-year old, 15-story tower, which was formerly known as the International Toy Center and designed by Maynicke & Franke.