US STOCKS-Wall St dips on UPS, miners; Starbucks jumps
* Indexes on track to break three-week streak of losses
* UPS shares fall after outlook, FedEx also lower
* Materials sector drags after Goldman notes
* Credit Suisse cuts Exxon to 'underperform'
* Dow down 0.5 pct, S&P 500 off 0.35 pct, Nasdaq up 0.2 pct (Updates to afternoon trading)
By Lucas Iberico Lozada
NEW YORK, Jan 23 (Reuters) - U.S. stocks fell modestly on Friday, pressured by underwhelming corporate news including guidance from economic activity bellwether UPS, which offset optimism triggered by the European Central Bank's decision to stimulate euro zone growth.
Materials shares weighed on the S&P 500, falling 1.3 percent in afternoon trading. Goldman cut its price target on Freeport McMoRan by 42 percent to $18 and cut prices on other miners, and separately slashed forecasts on commodity prices including aluminum, copper and nickel.
UPS was the largest drag on the S&P 500, followed closely by Exxon Mobil. On Friday Credit Suisse cut Exxon to "underperform." Continuación...