FLORHAM PARK, N.J. —Saiber LLC has signed a lease for more than 54,000 square feet of office space at 18 Columbia Turnpike in Florham Park. The law firm was originally based in Newark. It will be relocating its headquarters to the Florham Park office, which is located within Westminster Corporate Campus, a five-building, 180,000-square-foot office property. The space Saiber is leasing was originally occupied by Kushner Companies, which recently relocated its corporate headquarters to New York City. The company still maintains control over the property. Saiber will take occupancy in November. Terms of the lease were not disclosed.