SRL for [authorized]: Norfolk Southern Corp. directors [authorized] the railroad company to buy back as many as 45 million of its shares , which would have a current value of more than $ 1.7 billion .
ARG-0: Norfolk Southern Corp. directors | ARG-2: the railroad company | ARG-1: to buy back as many as 45 million of its shares , which would have a current value of more than $ 1.7 billion