By Pooja Menon (Reuters) -Dow CEO Jim Fitterling said on Thursday the polyethylene market is setting up for positive price action in September following a dip in the second quarter due to tariff uncertainties. "There's no sign that there's a massive inventory build. There's no sign of anything getting locked up or China falling out of the market to the point where it backed up exports," Fitterling said at the Morgan Stanley Laguna Conference. In the third quarter, the chemicals maker said it has observe ...