FRANKFURT - Lending to euro zone firms dipped into negative territory for the first time since 2015, data from the European Central Bank showed on Tuesday, as the bloc was likely in recession and facing a protracted recovery. Bank lending to businesses shrunk by 0.3 percent in October after a 0.2- percent expansion a month earlier while lending growth to households slowed to 0.6 percent from 0.8 percent, the ECB said. The M3 measure of money supply, seen in the past as a good indicator of future economic expansion, meanwhile picked up to minus 1 percent from minus 1.2 percent, not far from expectations for a 0.9- percent contraction.  ...Keep on reading: Euro zone corporate lending contracts as economy shrinks: ECB data