Wall Street lower as oil slips, earnings in focus

U.S. stocks were flat on Friday on worries that a potential deal by major oil producers to freeze output would do little to tackle a stubborn global oversupply. The nervousness about the outcome of the meeting overshadowed positive Chinese data, which showed the country's gross domestic product grew 6.7 percent in the first quarter in another sign that Asia's largest economy was on the mend. Citigroup reported a fall in quarterly profit, which still topped analysts' estimates.