The domestic stock markets opened higher tracking positive global cues. Gains were steady but selling pressure emerged at regular intervals. Buying momentum increased in the afternoon on positive European markets. The indices ended with modest gains near the day's highs. Technically, breadth was positive amid higher volumes indicating buying support. The markets are likely to have a flat opening as global cues are mixed ahead of the Federal Reserve meeting outcome. Key support and resistance levels for the Nifty are noted.