Indian equity indices opened lower, starting the week on a somber note amid weak global cues. Key economic data, including the GDP numbers that will be released later this week, and global cues will likely dictate the market trend going forward. The 30-share BSE benchmark Sensex declined 300 points or 0.52% at 59,157. The broader NSE Nifty dropped 90 points or 0.52% at 17,373.