Oct 21(Reuters) - Dow Inc on Thursday posted a more than five-fold jump in third-quarter profit, aided by strong demand and higher prices for chemicals as economies recover from the pandemic blow and tight supplies after Hurricane Ida. Net operating income, which excludes certain items, rose to $2.07 billion, or $2.75 per share, in the three months ended Sept. 30, from $376 million, or 50 cents per share, year earlier (Reporting by Rithika Krishna in Bengaluru; Editing by Sriraj Kalluvila)