Leon Manoff, executive managing director with Williams Real Estate, tells GlobeSt.com that the NPG deal and Viacom's 1.3-million-square foot renewal and expansion are part of an increasing trend. "Tenants are staying in place for a variety of reasons, many related to cost," he says. "They might be able to find space a little cheaper elsewhere, but after you factor in construction and moving expenses, it makes more sense to renew."

Manoff, who represented NPG in the lease, says the deal also illustrates the appeal of the Hudson Square area. "It's become a media hub," he says, noting that MTV Networks and New York magazine have relocated to the neighborhood in the past year and a half. The large floorplates of Hudson Square's office buildings are conducive to media operations, Manoff says, and the area itself "has developed a cachet."

In a release, Manoff also cites Williams Real Estate's 16-year relationship with NPG parent Macmillan Publishers as a factor in the deal's success. NPG publishes journals and online databases across the life, physical and applied sciences and, most recently, clinical medicine.