Nos. 2100, 2440, 98-4395, 99-4013. Argued September 1, 1999. Decided August 28, 2000. Viking Security, Inc. petitions for review of a November 30, 1998 supplemental decision and order of the National Labor Relations Board holding Viking derivatively liable for the backpay obligations of a now-dissolved company with which it once formed a "single employer." The Board cross-petitions for enforcement. Petition for review granted; petition for enforcement denied. RICHARD E. MILLER, New York, N.Y. (Kurzman