Wall Street set to open lower on earnings, oil prices

U.S. stock index futures gave up early gains and set Wall Street up to open slightly lower on Thursday as tepid earnings reports and economic data as well as drop in oil prices tempered enthusiasm. Shares of Dow component Verizon were off 2.5 percent in premarket trading after the wireless carrier reported a drop in quarterly revenue. American Express, also a Dow component, jumped 6.3 percent after its strong results and forecast.