NATM, MARTA Moving Offices NEW YORK— Two major buying groups, NATM Buying Corp. and MARTA Cooperative Of America, are on the move.NATM, which has been headquartered at Penn Plaza in midtown Manhattan for the past decade, is looking for new headquarters space by the time the lease is up in October. Executive director Bill Trawick said that the group will remain here, possibly in the borough of Queens.